Aspirin is one of the most commonly used drugs globally (Jones, 2005) and in the UK. Despite its wide availability and low price, last year in the UK, aspirin was prescribed more than 23 mln times (OpenPrescribing.net, 2019).
Aspirin belongs to a group of drugs called nonsteroidal anti-inflammatory drugs (NSAIDS). NSAIDs help to reduce pain, inflammation or help with fever symptoms. However, in this post, I will discuss a different use of low-dose aspirin, also known as baby aspirin. The following will be covered in this post:
- Definition and indicated use of baby aspirin
- Different forms of a low dose aspirin
- Possible side effects
What Is Baby Aspirin?
Baby aspirin refers to aspirin 75mg tablets. Low-dose aspirin is used as blood-thinning medicine to prevent the formation of blood clots.
What Is Baby Aspirin Used For?
- Secondary prevention of cardiovascular diseases. Secondary prevention means preventing the condition from happening again. Cardiovascular diseases covered by this use include:
- Long term management of patients who have had a ‘mini-stroke’ (combination with other drugs)
- The management of patients who have had an ischaemic stroke (stroke caused by blockage of a blood vessel in the brain) is not associated with atrial fibrillation (irregular heartbeat), usually combined with other drugs.
- prevention of clot formation following by-pass surgery
- prevention of myocardial infarction (heart attack)
- Prevention of pre-eclampsia in women who are at moderate or high risk (unlicensed use in pregnancy)
Low-dose aspirin is normally prescribed when used to treat the above conditions; however, some patients buy aspirin 75mg from a pharmacy under the recommendation of a doctor.
How Does Aspirin Help With The Secondary Prevention Of Cardiovascular Disease?
Low-dose aspirin is used in the secondary prevention of cardiovascular disease due to its antiplatelet properties. Secondary prevention relates to the prevention of subsequent cardiovascular episodes of heart attack, stroke, or death.
Antiplatelet treatment is recommended for patients with (NICE, 2018):
- Acute coronary syndrome (heart attack)
- Angina (chest pains)
- Atrial fibrillation (irregular heartbeats)
- Peripheral arterial disease, narrowing of blood vessels in arms, usually in legs, reduces blood flow to the affected area.
Additionally, antiplatelet treatment is recommended in patients who had (ibid):
- Heart attack
- Stent implanted
- Stroke or ‘mini’ stroke
Low-dose aspirin may be used on its own or in combination with other drugs to manage the above conditions.
Low Dose Aspirin: Prevention Of Pre-eclampsia In Pregnancy
Pre-eclampsia is a condition that can affect some pregnant women and is characterized by high blood pressure and usually the presence of protein in the urine. There is evidence to support the use of low-dose aspirin after the first trimester of pregnancy to reduce the development of pre-eclampsia (Fantasia, 2018).
NICE guideline on the management of pre-eclampsia advises daily use of baby aspirin (dose 75mg-150mg) from week 12 of pregnancy until the baby’s birth in women who are at high risk of this condition. The high risk applies to women who (NICE, 2019):
- High blood pressure during the previous pregnancy
- Kidney disease
- Have other conditions such as systemic lupus erythematosus or antiphospholipid syndrome
- Type 1 or type 2 diabetes
- Chronic hypertension
The same advice applies to women who have more than one moderate risk factor (ibid):
- First pregnancy
- Age 40 years or older
- The gap between pregnancies of more than 10 years
- Body mass index (BMI) of 35 kg/m2 (first visit)
- Family history of pre-eclampsia
- Multi-fetal pregnancy
Chronic hypertension in pregnancy may additionally be managed with other drugs such as labetalol.
The exact mechanism of aspirin in the prevention of pre-eclampsia is not known. Pre-eclampsia is characterized by the presence (and imbalance) of a certain ‘chemical’ called TXA2. TXA2 causes vasoconstriction (narrowing) of the blood vessels and consequently increases blood pressure.
The same chemical is also associated with inflammation. Aspirin belongs to a group of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). They reduce the production of TXA2 and hence counteract the vasoconstrictive effect (Wertaschnigg et al., 2019).
Baby Aspirin Dose
The usual daily dose of baby aspirin is one 75mg tablet daily. Depending on your medical condition, sometimes you may be asked to take a higher dose of aspirin. Please follow the recommendation of the prescriber.
Low-dose aspirin is usually taken in the morning with/after food to minimize the risk of gastrointestinal side effects.
Aspirin Dose for Pain Relief
Baby aspirin is not suitable for short-term pain relief, such as toothache, headache, or fever management.
Aspirin 300mg is usually taken to manage the pain or to help with the fever.
Dose recommendations range from 1-2 tablets taken every 4-6 hours. Read product information leaflet for dose instructions.
Who Cannot Have An Aspirin?
Aspirin should not be used by patients who:
- are under 16 years of age
- are suffering from stomach ulcers
- suffer from hemophilia (a condition characterized by a reduced ability of blood to clot)
Possible Side Effects Of Aspirin 75mg
Common side effects of baby aspirin include:
- Dyspepsia, nausea, vomiting, diarrhea
- Increased bleeding tendencies
Formulations Of Low Dose Aspirin
Aspirin 75mg tablets are available as:
- Dispersible tablets
- Gastro-resistant tablets
Additionally, aspirin 75mg is available as standard tablets, and it is a prescription drug.
As the name suggests, dispersible baby aspirin can be placed in the water and allowed to disintegrate before administration. Low-dose dispersible aspirin can be swallowed whole with a drink of water.
Gastro-resistant aspirin 75mg tablets (also known as enteric-coated tablets / EC) formulated to prevent dissolution in the stomach. Gastro-resistant formulation of low dose aspirin tablets was designed to minimize the risk of stomach irritation since EC formulation dissolves slowly, releasing the drug in the duodenum (small intestine) after the stomach.
However, there is not enough evidence to support the gastro-protective role of gastro-resistant aspirin (NECS, 2016). Additionally, conflicting opinions suggest that gastro-resistant aspirin may have reduced the antiplatelet effects compared to a standard release aspirin (ibid).
The ‘official’ NICE guideline advises against the use of gastro-resistant aspirin in patients who experience dyspepsia symptoms when treated with aspirin (NICE, 2018).
Where To Buy Baby Aspirin from?
Low-dose aspirin is available as a pharmacy-only medication (P). P medicines are available to purchase from a pharmacy (conventional or online).
The maximum legal quantity of aspirin 75mg sold in a single transaction is 100 tablets. Most pharmacies sell boxes or pots of branded aspirin 75mg dispersible tablets (100 per box/pot) priced under £2.
Branded versions of low dose aspirin include:
- Nu-Seals Cardio 75 (gastro-resistant tablets)
- Mandaprin 75mg Dispersible Tablets
- Fantasia, H.C., 2018. Low-dose aspirin for the prevention of preeclampsia. Nursing for women’s health, 22(1), pp.87-92. Available at: https://doi.org/10.1016/j.nwh.2017.12.002 Accessed on 25/02/2020
- Antiplatelet Trialists’ Collaboration, 1988. Secondary prevention of vascular disease by prolonged antiplatelet treatment. Br Med J (Clin Res Ed), 296(6618), pp.320-331. Available at: https://cks.nice.org.uk/antiplatelet-treatment#!scenario:1 Accessed on 25/02/2020
- Whellan, D.J., Goldstein, J.L., Cryer, B.L., Eisen, G.M., Lanas, A., Miller, A.B., Scheiman, J.M., Fort, J.G., Zhang, Y. and O’Connor, C., 2014. PA32540 (a coordinated-delivery tablet of enteric-coated aspirin 325 mg and immediate-release omeprazole 40 mg) versus enteric-coated aspirin 325 mg alone in subjects at risk for aspirin-associated gastric ulcers: results of two 6-month, phase 3 studies. American heart journal, 168(4), pp.495-502.Available at: https://medicines.necsu.nhs.uk/is-there-evidence-to-support-the-use-of-enteric-coated-ec-aspirin-to-reduce-gastrointestinal-side-effects-in-cardiovascular-patients/ Accessed on 20/06/2019
- Wertaschnigg, D., Reddy, M., Mol, B.W., da Silva Costa, F. and Rolnik, D.L., 2019. Evidence-based prevention of preeclampsia: commonly asked questions in clinical practice. Journal of pregnancy, 2019. Available at: https://doi.org/10.1155/2019/2675101 Accessed on 25/02/2020