Precautions and considerations for taking aspirin

Precautions and considerations for taking aspirin

Precautions and considerations for taking aspirin

Medication and medical condition interactions are generally classified according to severity. A general guideline is as follows:

  • Major: This means that an interaction is deemed highly clinically significant. Thus, the risk of the interaction occurring may outweigh any possible benefit of using aspirin. Generally, medication combinations that include aspirin may not be recommended, and an alternate therapy plan with fewer risk factors will be implemented instead.
  • Moderate: This means that an interaction is moderately clinically significant and may be considered in specific circumstances where some benefit may be gained from the use of aspirin while under strict monitoring care. The rule of thumb is to avoid specific medication combinations with high risks and consider alternatives in order to achieve the desired treatment effect.
  • Minor: A potential interaction is minimally clinically significant, meaning that any risk is reasonably low. A doctor may consider alternative medication combinations to minimise the likelihood of an adverse reaction (where relevant) or initiate a careful monitoring plan of action.
  • Unknown: In this instance, no conclusive data is available for why an interaction may occur. Many side-effects are listed as reported associations with aspirin, but a direct causal link has not been precisely determined or the quality of study evidence is too small or varied to yield conclusive results.

1. Medication interactions

When using aspirin, it is important to acknowledge that when taken simultaneously with other medications / medication classes or substances (including natural or herbal varieties), adverse reactions can occur. Interactions which can occur, and their severity, typically depend on…

  • The dosage taken
  • The frequency of dosages taken
  • The form of medication taken (orally taken forms sometimes have a greater effect on more of the body than just one system or organ)
  • How the medication is absorbed, metabolised and expelled from the body (e.g. via the gastrointestinal tract, liver and kidneys)
  • The coadministration of other substances in the system
  • A person’s predisposition to certain reactions

There are hundreds of medications and substances known to interact with aspirin to some degree. We have listed a fair majority here. If in doubt, especially if an existing medical condition has been diagnosed already and is under treatment, it is best to seek a professional opinion from a doctor before taking aspirin. Short-term low dosages may not cause severe reactions, but caution is advised.

List of notable medications known to interact adversely when co-administered with aspirin

Interaction possibility (when taken with aspirin)
Contraindicated (i.e. these medications should never be taken with aspirin) Dichlorphenamide (Keveyis and Daranide) - a carbonic anhydrase inhibitor often used to treat glaucoma and primary periodic paralysis / loss of movement. Used with high doses of aspirin, this medication may elevate salicylate concentration levels in the bloodstream. Reported side effects in this regard include rapid / abnormal breathing problems, lethargy, anorexia and coma.
Mifepristone (Mifegyne and Mifeprex) - typically used to induce an abortion. Anti-platelet activity can increase the risk of excessive bleeding following an abortion.
Ketorolac (Toradol, Acular and Sprix) – used in the treatment of mild to moderate pain and inflammation.

Ketorolac intranasal (nasal spray)
Toxicity is increased in either medication when taken in combination.
Serious interaction (alternative medication combinations are recommended) Benazepril (Lotensin) – used in the treatment of hypertension, heart attack and congestive heart failure.

Captopril (Capoten) – used in the treatment of hypertension, heart attack, congestive heart failure and diabetic-associated kidney dysfunction.

Enalapril (Vasotec) – used in the treatment of hypertension, diabetic-associated kidney dysfunction and congestive heart failure.

Fosinopril (Monopril) – used in the treatment of hypertension and chronic heart failure.

Lisinopril (Prinivil and Zestril) – used to treat hypertension, heart attack and heart failure.

Moexipril (Univasc) – used in the treatment of hypertension and congestive heart failure.

Perindopril (Coversyl, Coversum, Preterax or Aceon) – used in the treatment of hypertension, heart failure and stable coronary artery disease.

Quinapril (Accupril) – used for the treatment of hypertension and congestive heart failure.

Ramipril (Altace) – used to treat hypertension and congestive heart failure.

Trandolapril (Mavik) – used in the treatment of hypertension and to prevent recurring heart attack.
Significant decrease in kidney function.
Ibuprofen (Advil, Motrin and Nurofen) – used in the treatment of pain, fever and inflammation

Ibuprofen IV / intravenous (Caldolor)
Decreased therapeutic effect of aspirin. Ibuprofen also reduces the anti-platelet effects of aspirin, increasing toxicity (leading to anticoagulation / lack of the ability to clot) which enhances the risk of bleeding.
Lesinurad (Zurampic) – used to treat gout induced hyperuricaemia (excess uric acid in the blood). Aspirin in high dosages decreases the therapeutic effect of this medication. Lower dosages can be recommended with minimal interference between the medications if coadministration is deemed necessary (i.e. a doctor decides that the benefits outweigh the risks).
Macimorelin – used in the treatment of adult growth hormone deficiency. Aspirin may interfere with the accuracy of the necessary diagnostic tests. Tests should only be conducted once aspirin has been sufficiently eliminated from the body (where relevant).
Measles, mumps, rubella (German measles) and varicella (Chickenpox) vaccine (live) Salicylate toxicity may be enhanced. For young children and adolescents, there is an increased risk of the development of Reye’s syndrome (a rare, but severe condition that results in swelling in the brain and liver) as the vaccine contains live or attenuated viruses. Aspirin should not be used for a minimum of 6 weeks following vaccination to alleviate this risk.
Methotrexate (Trexall and Rheumatrex) – used in the treatment of cancer, autoimmune conditions (as an immunosuppressant) and ectopic pregnancies (a pregnancy in which a fertilised egg implants outside of the uterus. Aspirin elevates blood serum concentrations of this medication which results in reduced clearance from the body via the kidneys. Interaction risk is highest when high dosages of this medication are used. Low dosages of either medication used simultaneously should be very closely monitored.
Pemetrexed (Alimta) – used to treat pleural mesothelioma and non-small cell lung cancer (chemotherapy). Aspirin elevates blood serum concentrations of this medication. If used simultaneously, medical monitoring will keep a close eye on potential myelosuppression (decreased bone marrow activity), renal and gastrointestinal toxicity reactions.
Probenecid (Probalan) – used in the treatment of gout induced hyperuricaemia (excess uric acid in the blood). Aspirin decreases the therapeutic effect of this medication causing renal tubular clearance difficulties.
Ticlopidine (Ticlid) – used for the prevention of stroke (ischemic and TIA) and the formation of blood clots within stents that are placed in the heart.  

Moderate interaction medications and other substances (when coadministration use with aspirin)

Some medications and substances induce moderate adverse effects which, if used with aspirin, will require medical monitoring. Alternatively, therapy combinations can be modified.

Substances include medications belonging to various drug classes such as platelet aggregation inhibitors and anticoagulants (both of which prevent the formation of clots), NSAIDs (non-steroidal anti-inflammatories), alpha blockers and beta blockers (which are used to treat high blood pressure amongst other conditions), antidepressants, antibiotics, corticosteroids (which reduce inflammation), diuretics (also called water pills), oral contraceptives, blood sugar lowering agents etc., as well as organic / plant-based compounds and substances (herbs).

Some interactions according to medication class type include:

  • Antiplatelet medications - These medications can result in salicylate toxicity, which can increase a person’s risk of bleeding, gastrointestinal ulceration and bruising. The antiplatelet effect of these medications in the system can be enhanced as well, further inducing toxicity.
  • Anticoagulants - These medications have anti-platelet properties. The use of aspirin in conjunction with these may worsen the anticoagulant (blood thinning) effect of these medications. This increases the risk of bleeding.
  • Thrombolytic agents: Aspirin may intensify the anticoagulant effect of these types of medications, enhancing the toxic effect and thereby elevating the risk for bleeding.
  • Non-steroidal anti-inflammatories (NSAIDs) – These medications, especially when used along with higher dosages of aspirin, can result in a significantly enhanced risk of gastrointestinal problems, such as ulceration and bleeding. If it is necessary to use these medications simultaneously, a medical doctor may adjust the dosages, monitor a patient periodically and recommend proton pump inhibitors (medications that reduce the production of stomach acid) to alleviate complications or side-effects.
  • Angiotensin-Converting Enzyme (ACE) Inhibitors - Simultaneous use of aspirin with these medications can enhance toxicity in the kidneys (this is referred to as having a nephrotoxic effect) which affects proper renal function. Aspirin can also reduce the therapeutic effect of ACE inhibitors.
  • Blood glucose lowering agents - Aspirin can intensify the hypoglycaemic (blood sugar lowering) effect of these medications which can result in adverse reactions such as confusion, clumsiness and even loss of consciousness.
  • Calcium channel blockers (Nondihydropyridine) – These medications typically function to disrupt the movement of calcium in the body and are used to treat conditions like angina, heart arrythmia (abnormal heart beat) and hypertension (high blood pressure) - The anti-platelet effect of aspirin that results in blood thinning may be heightened when these medications are taken simultaneously.
  • Medications with antiarrhythmic agents or properties - Aspirin can worsen the toxic effect of medications with antiarrhythmic properties (i.e. the ability to suppress an abnormal heart rhythm). One such effect may be a higher risk for cholestasis (reduced bile flow from the liver).
  • Carbonic Anhydrase Inhibitors – These medications suppress the activity of carbonic anhydrase by reducing the formation of bicarbonate ions and hydrogen from carbon dioxide and water. Aspirin taken simultaneously can result in salicylate toxicity which has a number of symptoms including nausea, vomiting, excessive perspiration (diaphoresis) and tinnitus (ringing in the ears) in its early stages.
  • Bisphosphonate medications – These medications are often used in the treatment of osteoporosis and other bone diseases, such as Paget’s disease (a softening or weakening of the bones causing pain, as well as risk of fractures and deformities). Aspirin can worsen the toxic effect of these medications, resulting in gastrointestinal problems.
  • Uricosuric agent medications - Aspirin may reduce the therapeutic effect of these medications by decreasing their serum concentrations in the bloodstream.
  • Muscle relaxant medications – These medications help to alleviate pain due to muscle spasms and promote improved muscle control or function. Aspirin may elevate the serum concentrations of active metabolites, decreasing the therapeutic effect of these medications.
  • Antibiotic medications - Taken along with aspirin can intensify the toxic effect of the antibiotic medication, increasing the risk of bleeding.
  • Corticosteroid (systemic) medications / steroid hormones - Aspirin may worsen the toxic effect of these medications, resulting in bleeding or gastrointestinal ulceration. These medications may also reduce the serum concentration of aspirin in the bloodstream. Corticosteroid withdrawal can also result in salicylate toxicity.
  • Medications used in the treatment of cancer / immune system suppressants for autoimmune conditions – Anticoagulant (anti-clotting) effects may be enhanced with the use of these medications when taken with aspirin. This increases the risk of bleeding.
  • Diuretics – The therapeutic effect of such substances may be reduced when taken alongside aspirin medications. Diuretics can also elevate serum concentrations of salicylates in the blood, causing adverse symptoms.
  • Hyaluronidases (enzymes used to help absorb other injected medications as well as in contrast dyes used in X-rays and scans) – Aspirin may interfere with the therapeutic effect of these types of medications. Larger doses of hyaluronidases may be used to enhance the desired clinical effect. Alternative therapies can also be considered.
  • Herbal substances and compounds – These may worsen the anticoagulant effect of aspirin and induce bleeding.
  • Multivitamins and mineral supplements (including omega-3 fatty acids and vitamin E) – The anti-platelet effect of aspirin may be enhanced with this combination. Aspirin can reduce the serum concentration of certain multivitamins (containing folate, iron or fluoride), as well as reduce the rate of absorption of ascorbic acid.
  • Potassium phosphate – The serum concentration of salicylates may be enhanced with this compound in the system.

Some medications included on the moderate interaction list are:

A / B
C / D
E / F
  • Abciximab
  • Acalabrutinib
  • Acebutolol
  • Aceclofenac
  • Acemetacin
  • Acetazolamide
  • Agrimony
  • Albuterol
  • Alfalfa
  • Alfuzosin
  • Aliskiren
  • Alteplase
  • American ginseng
  • Amiloride
  • Amoxicillin
  • Ampicillin
  • Anagrelide
  • Antithrombin alfa
  • Antithrombin iii
  • Apixaban
  • Arformoterol
  • Argatroban
  • Asenapine
  • Atenolol
  • Azficel-t
  • Azilsartan
  • Bambuterol
  • Bemiparin
  • Bendroflumethiazide
  • Betaxolol
  • Betrixaban
  • Bisoprolol
  • Bivalirudin
  • Brinzolamide
  • Bumetanide
  • Candesartan
  • Carbenoxolone
  • Carvedilol
  • Celecoxib
  • Celiprolol
  • Chlorothiazide
  • Chlorpropamide
  • Chlorthalidone
  • Choline magnesium trisalicylate
  • Cilostazol
  • Cinnamon
  • Ciprofloxacin
  • Citalopram
  • Clobetasone
  • Clomipramine
  • Clopidogrel
  • Collagenase clostridium histolyticum
  • Cordyceps
  • Cortisone
  • Cyclopenthiazide
  • Dabigatran
  • Dalteparin
  • Deferasirox
  • Defibrotide
  • Deflazacort
  • Desirudin
  • Dexamethasone
  • Diclofenac
  • Dicloxacillin
  • Diflunisal
  • Digoxin
  • Dipyridamole
  • Dobutamine
  • Dong quai
  • Dopexamine
  • Doxazosin
  • Drospirenone
  • Duloxetine
  • Edoxaban
  • Elvitegravir /cobicistat / emtricitabine / tenofovir df
  • Enoxaparin
  • Ephedrine
  • Ephedrine (pulmonary)
  • Epinephrine
  • Epinephrine racemic
  • Epoprostenol
  • Eprosartan
  • Eptifibatide
  • Escitalopram
  • Esmolol
  • Ethacrynic acid
  • Etodolac
  • Etoricoxib
  • Fenbufen
  • Fennel
  • Fenoprofen
  • Feverfew
  • Fish oil
  • Flucloxacillin
  • Fludrocortisone
  • Fluoxetine
  • Flurbiprofen
  • Fluvoxamine
  • Fondaparinux
  • Formoterol
  • Forskolin
  • Furosemide
G / H / I
K / L / M / N
O / P /R
  • Garlic
  • Gentamicin
  • Ginger
  • Ginkgo biloba
  • Glimepiride
  • Glipizide
  • Gliquidone
  • Glyburide
  • Green tea
  • Griseofulvin
  • Heparin
  • Horse chestnut seed
  • Hyaluronidase
  • Hydralazine
  • Hydrochlorothiazide
  • Hydrocortisone
  • Icosapent
  • Imatinib
  • Indapamide
  • Indomethacin
  • Insulin aspart
  • Insulin aspart protamine / insulin aspart
  • Insulin degludec
  • Insulin degludec / insulin aspart
  • Insulin detemir
  • Insulin glargine
  • Insulin glulisine
  • Insulin inhaled
  • Insulin isophane human/insulin regular human
  • Insulin lispro
  • Insulin lispro protamine/insulin lispro
  • Insulin nph
  • Insulin regular human
  • Irbesartan
  • Isoproterenol
  • Ketoprofen
  • Labetalol
  • Lepirudin
  • Levalbuterol
  • Levomilnacipran
  • Lithium
  • Lornoxicam
  • Losartan
  • Meclofenamate
  • Mefenamic acid
  • Melatonin
  • Meloxicam
  • Mesalamine
  • Metaproterenol
  • Methazolamide
  • Methyclothiazide
  • Methylprednisolone
  • Metolazone
  • Metoprolol
  • Milnacipran
  • Mistletoe
  • Moxisylyte
  • Mycophenolate
  • Nabumetone
  • Nadolol
  • Nafcillin
  • Naproxen
  • Nebivolol
  • Nefazodone
  • Nettle
  • Nitazoxanide
  • Nitroglycerin rectal
  • Nitroglycerin sublingual
  • Norepinephrine
  • Olmesartan
  • Omega 3 carboxylic acids
  • Omega 3 fatty acids
  • Ospemifene
  • Oxacillin
  • Oxaprozin
  • Panax ginseng
  • Parecoxib
  • Paroxetine
  • Pau d'arco
  • Pegaspargase
  • Penbutolol
  • Penicillin g aqueous
  • Phenindione
  • Phenoxybenzamine
  • Phentolamine
  • Phytoestrogens
  • Pindolol
  • Pirbuterol
  • Piroxicam
  • Pivmecillinam
  • Potassium acid phosphate
  • Potassium chloride
  • Potassium citrate
  • Prasugrel
  • Prazosin
  • Prednisolone
  • Prednisone
  • Propranolol
  • Protamine
  • Reishi
  • Reteplase
  • Rivaroxaban
  • Rivastigmine
V / W / Z
  • Sacubitril/valsartan
  • Salicylates (non-asa)
  • Salmeterol
  • Salsalate
  • Saw palmetto
  • Sertraline
  • Siberian ginseng
  • Silodosin
  • Sodium picosulfate/magnesium oxide/anhydrous citric acid
  • Sotalol
  • Spironolactone
  • Succinylcholine
  • Sulfamethoxazole
  • Sulfasalazine
  • Sulindac
  • Telmisartan
  • Temocillin
  • Tenecteplase
  • Terazosin
  • Terbutaline
  • Ticagrelor
  • Ticarcillin
  • Timolol
  • Tinzaparin
  • Tirofiban
  • Tobramycin inhaled
  • Tolazamide
  • Tolbutamide
  • Tolfenamic acid
  • Tolmetin
  • Tolvaptan
  • Torsemide
  • Trazodone
  • Triamcinolone acetonide injectable suspension
  • Triamterene
  • Valproic acid
  • Valsartan
  • Venlafaxine
  • Vorapaxar
  • Vortioxetine
  • Warfarin
  • Zotepine

Minor interaction medications and other substances (when co-administered with aspirin)

Medical monitoring may be required as needed for any of the following:

A / B
C / D
E / F / G / H / I
  • Aceclofenac
  • Acemetacin
  • Acyclovir
  • Alendronate
  • Aluminium hydroxide
  • Amikacin
  • Aminohippurate sodium
  • Anamu
  • Ascorbic acid
  • Balsalazide
  • Bendroflumethiazide
  • Bismuth subsalicylate
  • Bumetanide
  • Calcium carbonate
  • Cefadroxil
  • Cefamandole
  • Cefepime
  • Cefixime
  • Cefpirome
  • Cefprozil
  • Ceftazidime
  • Ceftibuten
  • Ceftizoxime
  • Celecoxib
  • Cephalexin
  • Chlorothiazide
  • Chlorpropamide
  • Chlorthalidone
  • Choline magnesium trisalicylate
  • Chromium
  • Clobetasone
  • Cortisone
  • Creatine
  • Cyanocobalamin
  • Cyclopenthiazide
  • Danshen
  • Deflazacort
  • Devil's claw
  • Dexamethasone
  • Diclofenac
  • Diclofenac topical
  • Diflunisal
  • Diltiazem
  • Eplerenone
  • Ethanol
  • Etodolac
  • Etoricoxib
  • Fenbufen
  • Fenoprofen
  • Feverfew
  • Fludrocortisone
  • Flurbiprofen
  • Folic acid
  • Furosemide
  • Ganciclovir
  • Gentamicin
  • Glimepiride
  • Glipizide
  • Gliquidone
  • Glyburide
  • Hydrochlorothiazide
  • Hydrocortisone
  • Imidapril
  • Indapamide
  • Indomethacin
K / L / M / N / O
P / R / S
T / V / W / Z
  • Kanamycin
  • Ketoprofen
  • L-methylfolate
  • Lornoxicam
  • Meclofenamate
  • Mefenamic acid
  • Meloxicam
  • Mesalamine
  • Methyclothiazide
  • Methylprednisolone
  • Metolazone
  • Nabumetone
  • Naproxen
  • Neomycin po
  • Netilmicin
  • Noni juice
  • Ofloxacin
  • Oxaprozin
  • Parecoxib
  • Paromomycin
  • Penicillin vk
  • Pentazocine
  • Piperacillin
  • Piroxicam
  • Prednisolone
  • Prednisone
  • Rose hips
  • Salicylates (non-asa)
  • Salsalate
  • Sodium bicarbonate
  • Sodium citrate/citric acid
  • Streptomycin
  • Sulfadiazine
  • Sulfasalazine
  • Sulfisoxazole
  • Sulindac
  • Teniposide
  • Tiludronate
  • Tobramycin
  • Tolazamide
  • Tolbutamide
  • Tolfenamic acid
  • Tolmetin
  • Triamcinolone acetonide injectable suspension
  • Triamterene
  • Valganciclovir
  • Vancomycin
  • Verapamil
  • Willow bark
  • Zafirlukast
  • Zoledronic acid

Young woman experiencing stomach pain or discomfort.

2. Interactions associated with medical conditions

The use of aspirin is contraindicated or cautioned in the following instances:

Risk category
Medical condition
What happens…
Major Coagulation disorders (includes risk of bleeding, thrombocytopathy / disorders of the blood, thrombocytopenia / low blood platelet count and vitamin K deficiency) Bleeding and haemorrhagic disorders are contraindicated for aspirin use. Aspirin inhibits platelet accumulation, thereby interfering with coagulation (clotting) function. This can result in problems with bleeding due to impaired blood clotting reactions.

Salicylates can also interfere with the mechanistic action of vitamin K (this vitamin plays an important role in helpful blood clotting and bone metabolism).

Extreme caution is recommended for patients with blood disorders, like hypoprothrombinaemia, thrombocytopenia, thrombotic thrombocytopenic purpura, vitamin K deficiencies and even individuals with severe liver impairments.
Major Asthma (including the use of NSAID medications for treatment) A percentage of asthmatic patients may be particularly sensitive to aspirin, resulting in the development of nasal polyps, sinus infections, eosinophilia (high levels of white blood cells in the bloodstream), and even rhinitis (mucous membrane swelling resulting in nasal irritation, a stuffy nose or hay fever symptoms). In more severe instances, bronchospasm (narrowing of the bronchi and spasm of the bronchial muscle) and life-threatening anaphylactoid reactions can occur.

Caution is recommended in any asthmatic patient, and especially those with a history of aspirin or NSAID sensitivity or allergic reactions.

In some cases, low dosage combinations of medications may be used and strictly monitored. Where particularly sensitive and adverse reactions occur, the combination is not recommended.
Major Gastrointestinal toxicity (applicable to patients with peptic ulcers, gastritis, gastrointestinal perforation or haemorrhage, colitis, enteritis, colonic ulceration or a history of alcoholism) Mucosal damage (injury to the gastric mucosa or lining of the digestive tract) and gastrointestinal bleeding can occur when aspirin is taken. If taken chronically, iron deficiency anaemia can also occur.

Upper gastrointestinal bleeding is most typical in patients with active peptic (stomach) ulcers or who have recently experienced a bleeding event. Mucosal damage may also result in the development of peptic ulcers, which may or may not experience bleeding. Latent ulcers can also be reactivated, or ulcer perforation may occur.

Extreme caution is recommended especially for those individuals with a history of gastrointestinal troubles, ulceration and bleeding. Careful consideration will also be necessary for individuals with a history of excessive alcohol use as well as in seniors (the elderly). Such patients are likely to be at higher risk of gastrointestinal toxicity and often do not tolerate such adverse reactions well.

A doctor is likely to try other medication combinations first when treating a patient. If aspirin containing medications are used, close monitoring is required. Other medications (often at higher dosages), such as antacids, may be recommended to try and counteract potential ulcer formation.
Major Renal / Kidney dysfunction Since salicylates and associated metabolites are eliminated from the body via the kidneys, patients with any organ impairments could result in adverse reactions.

A doctor may consider lower dosages of aspirin so as to avoid an accumulation of the medication in the kidneys. If the administration of aspirin is necessary for extended periods of time, clinical monitoring is highly recommended.

Adverse reactions can include elevations in serum creatinine, renal papillary necrosis (death of kidney papillae which transport urine produced in one section of the kidney to another before it is expelled) and acute tubular necrosis (death of tubular epithelial cells). Renal failure can develop. Other impairments can result in reduced renal blood flow which can be reversed once aspirin therapy is withdrawn.
Major Reye’s syndrome (mainly applicable for influenza / flu infections and varicella-zoster viruses – causing chickenpox and shingles) Children are susceptible to adverse reactions when taking aspirin while viral infections are active (or during recovery from a viral infection). The primary risk for children is the development of Reye’s syndrome– a rare but severe condition that is characterised by acute noninflammatory encephalopathy (damage to the brain) and fatty degenerative liver failure.

Thus, it is not recommended for children and teenagers to take aspirin, especially when a virus is active or there is an outbreak in the area. Other non-aspirin-based antipyretics (medications that reduce fever) and analgesics (painkillers) are typically the preferred alternative medication therapy.
Moderate Dialysis (kidney / haemodialysis) Dialysis refers to the process of cleaning out the blood of a patient whose kidneys are not functioning sufficiently.

Typically, aspirin doses are not recommended for a patient on dialysis. If necessary, such doses can be scheduled following dialysis administration.

During the dialysis process salicylates and their metabolites are removed from the blood, rendering the medication ineffective for any treatment purposes. If required, supplemental doses can be given after dialysis.
Moderate G-6-Pd Deficiency (glucose-6-phosphate-dehydrogenase deficiency) A patient with this condition may experience some disruption in the haemolysis process (the breakdown of red blood cells before their normal lifespan is expected to end) when taking aspirin.

A doctor will recommend aspirin cautiously if required for treatment purposes.
Moderate Hepatotoxicity (applicable to liver disease) Hepatotoxicity can occur as a result of blood serum salicylate concentrations. Such reactions are generally acute but reversible. Elevations of serum transaminases and alkaline phosphatase (enzymes) can occur.

High dosages may be considered but will be very carefully monitored. Periodic liver function checks will likely be recommended. Should liver function problems arise during treatment, dosages are likely to be reduced to minimise toxicity effects or ceased altogether.

Midsection of a pregnant woman pouring pills into her hand.

3. Pregnancy

Salicylates, including aspirin may be able to cross the placenta during pregnancy (2) and thus adversely affect a developing foetus. Interaction may result in intrauterine growth retardation, salicylate toxicity, bleeding problems and neonatal acidosis. If a pregnant woman uses aspirin close to her delivery date, premature closure of the ductus arteriosus (a foetal artery connecting the main body artery (aorta) and the main lung artery (pulmonary artery) may occur, which can result in persistent foetal pulmonary hypertension (a type of high blood pressure that affects the arteries of the lungs and right side of the heart). A pregnant woman can also experience problems with anaemia, prolonged gestation or even prolonged labour due to aspirin use.

Chronic and even high intermittent dosages of aspirin are generally not recommended. Increased risk of haemorrhage is one concern in this regard affecting both the mother and her unborn baby. Low dosages of aspirin can sometimes be used in an effort to prevent the development of pre-eclampsia, especially if a woman has a history of the condition. This can also help to prevent pre-term delivery of a baby. Low aspirin dosages are also sometimes used in the treatment of complications which occur as a result of antiphospholipid syndrome, an autoimmune disorder which affects the blood. Complications can include the development of blood clots in the body. Further complications could include miscarriage or stillbirth. Low-dose aspirin usage during pregnancy is intended for blood thinning purposes so as to prevent blood clots and thrombosis.

During the third trimester, aspirin is typically not recommended for use by pregnant women as this can result in adverse reactions to the unborn baby, including premature closure of a vessel in the foetus’s heart. It can also result in an increased risk of complications during delivery.

4. Lactation / breastfeeding

As in the case of pregnancy, salicylates may also occur in breast milk of a lactating woman. If a mother has used aspirin during the nursing period, a breastfed baby may be exposed to this medication. Exposure may be calculated according to the highest concentration levels in breast milk (relative infant dose / RID). Higher concentration levels may apply where a mother has taken multiple doses of aspirin. An infant tends to experience a longer elimination half-life than adults, which means that exposure takes more time to be cleared from the body. For the mother, concentrations of the medication in breast milk may also be slowly eliminated from the body.

A baby is at risk of developing metabolic acidosis whereby acid is produced in excessive amounts or the kidneys are unable to adequately remove acid from the body. Another problem which can occur is thrombocytopenic purpura (low platelet levels which can result in bleeding and bruising).

Chronic or long-term therapy using aspirin is generally not recommended for breastfeeding mothers, with non-opioid analgesics being preferred for the treatment of pain.

Close-up of ground and whole curry powder and turmeric in bowls on a wooden table.

5. Dietary factors / food interactions

Aspirin may interact with certain foodstuffs as well. Interactions are generally considered to be relatively minor, however. Certain foods can have a slight impact on the rate of absorption when aspirin is taken orally, reducing it a little. Some may even contribute to the accumulative concentrations of salicylates.

Foods and substances that may interact with aspirin
Interaction – factors to keep in mind
Prunes and raisins
Tea (caffeine content)
Herbal liqueurs (such as Benedictine liqueur)
Curry powder
These food and beverage items may result in the accumulation of salicylate concentrations in the body. Some of these items (such as paprika, curry powder and liquorice) contain salicylate themselves, contributing to higher concentration levels in the blood.
Vitamin C containing fruits These foods may promote the increased excretion of aspirin through urine.

Minor interactions with these foods can sometimes be alleviated by ensuring that aspirin is taken with food or a large volume of either milk or water. This can alleviate some gastrointestinal troubles which can be experienced when it is ingested simultaneously with these foods. Limiting one’s consumption of curry powder, paprika and liquorice can also be beneficial.

Of all foodstuffs, alcohol (ethanol) is possibly the substance which could have the greatest impact in terms of interaction. Alcohol and aspirin interaction may be considered more in a moderate capacity (as it may not affect all patients), however it is advisable that the combination be avoided. The combination of alcohol and aspirin taken together may increase a person’s risk of bleeding – most often within the stomach or intestines. Alcohol can increase the existing bleeding risk of aspirin. Prostaglandins may be inhibited, rendering them ineffective for helping to ease inflammation or moderate blood blow. The function of the gastrointestinal lining thus also becomes compromised, contributing to increased risk of bleeding.

Some indications that bleeding may be occurring include stools which contain blood, appear black (or darker in colour) and tarry, vomit that resembles coffee grounds or blood that is coughed up.

Alcohol can also reduce the therapeutic effect of aspirin. Generally, medical doctors do not recommend the consumption of alcohol when aspirin or aspirin containing medications are being taken. A doctor will generally not recommend the taking of aspirin if it is determined that a patient is in the habit of consuming more than 3 alcoholic beverages on a regular basis (i.e. daily). (3) The risk of bleeding may be higher in some individuals and in others the interaction may not be clinically relevant. If a noticeable interaction occurs, it is best to consult a medical professional for an evaluation and appropriate guidance with regards to treatment options.


2. US National Library of Medicine - National Institutes of Health. January 2008. Aspirin and Reproductive Outcomes: [Accessed 22.06.2018]

3. US Food and Drug Administration. December 2015. Aspirin - Questions and Answers: [Accessed 22.06.2018]

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