Aspirin is one of the most commonly used drugs in the world (Jones, 2005) and 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 can be taken to reduce pain, inflammation or help with fever symptoms, however, in this post, I will be talking about 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) not associated with atrial fibrillation (irregular heartbeat), usually in combination 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 in the treatment of 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?
A 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, which 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
A 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 which can affect some pregnant women and is characterised by high blood pressure and usually presence of protein in the urine. There is a 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 birth of the baby in women who are at high risk of this condition. 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 prevention of pre-eclampsia is not known. Pre-eclampsia is characterised by the presence (and imbalance) of a certain ‘chemical’ called TXA2. TXA2 causes vasoconstriction (narrowing) of the blood vessels and consequently increase of blood pressure. The same chemical is also associated with inflammation. Aspirin, which belongs to a group of drugs called nonsteroidal anti-inflammatory drug (NSAIDs) reduce the production of TXA2 and hence counteracts 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 minimise the risk of gastrointestinal side effects.
What dose of aspirin is taken for pain relief?
Baby aspirin is not suitable for the short-term relief of pain, such as toothache or headache or the management of fever.
Aspirin 300mg is normally 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 haemophilia (a condition characterised by a reduced ability of blood to clot)
Possible side effects of aspirin 75mg
Common side effects of baby aspirin include:
- Dyspepsia, nausea, vomiting, diarrhoea
- Increased bleeding tendencies
Formulations of low dose aspirin
Aspirin 75mg tablets that can be purchased from the pharmacy are available as:
- Dispersible tablets
- Gastro-resistant tablets
Additionally, aspirin 75mg is available as standard tablets, which can be prescribed only.
As the name suggests dispersible baby aspirin can be placed in the water and allow 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) are formulated to prevent dissolution in the stomach. Gastro-resistant formulation of low dose aspirin tablets was designed to minimise 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, there are conflicting opinions suggesting that gastro-resistant aspirin may have reduced the antiplatelet effects as 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?
A low dose aspirin is available as pharmacy only medication (P). P medicines can be purchased from a pharmacy (conventional or online). The maximum legal quantity of aspirin 75mg that can be sold in a single transaction is 100 tablets. Most pharmacies sell boxes or pots of own branded aspirin 75mg dispersible tablets (100 per box/pot) priced under £2. Branded versions of low dose aspirin include:
- Nu-Seals Cadio 75 (gastro-resistant tablets)
- Mandaprin 75mg Dispersible Tablets
When should I take baby aspirin?
Low dose aspirin is usually taken in the morning with/after food.
What is baby aspirin good for?
Baby aspirin can be taken for the management of different conditions including secondary prevention of cardiovascular diseases, pre-eclampsia (in pregnancy) and management of some ischaemic strokes.
Is baby aspirin a blood thinner?
Baby aspirin stops aggregation (coming together) of platelets causing reducing the risk of serious cardiovascular events such as myocardial infarction, stroke.
Fantasia HC. Low-Dose Aspirin for the Prevention of Preeclampsia. Nurs Womens Health. 2018;22(1):87–92. doi:10.1016/j.nwh.2017.12.002 Available at: https://doi.org/10.1016/j.nwh.2017.12.002 Accessed on 25/02/2020
Jones Alan (2005). Chemistry: An Introduction for Medical and Health Science, John Wiley and Sons Ltd
NICE (2018). Antiplatelet treatment.Scenario: Antiplatelet treatment for secondary prevention of cardiovascular disease (CVD). Available at: https://cks.nice.org.uk/antiplatelet-treatment#!scenario:1 Accessed on 25/02/2020
NICE (2019). Hypertension in pregnancy: diagnosis and management. Available at: https://www.nice.org.uk/guidance/ng133/chapter/Recommendations#management-of-pre-eclampsia Accessed on 25/02/2020
NECS (2016). Is there evidence to support the use of enteric-coated (EC) aspirin to reduce gastrointestinal side effects in cardiovascular patients? 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
OpenPrescrbing.net (2019). Aspirin. Available at: https://openprescribing.net/chemical/0209000A0/ Accessed on 21/06/2019
Wertaschnigg, Dagmar, Reddy, Maya, Mol, Ben W. J, da Silva Costa, Fabricio, Rolnik, Daniel L. (2019). Evidence-Based Prevention of Preeclampsia: Commonly Asked Questions in Clinical Practice. Available at: https://doi.org/10.1155/2019/2675101 Accessed on 25/02/2020