- NSAIDs: They are ibuprofen, diclofenac, aspirin and naproxen help to relieve pain and fever, and can reduce swelling and inflammation. They work at the site of the pain by reducing the production of prostaglandins in the brain and in the tissues surrounding the damaged area. Ibuprofen can be given to children from three months of age in liquid form. For adults, ibuprofen is available as tablets, capsules, gels and patches to treat most types of pain. People who have or have had asthma or stomach ulcers should speak to the pharmacist before taking ibuprofen. Eg. Nurofen 200mg, Cuprofen Maximum Strength Tablets.
Restrictions on the use of paracetamol, aspirin and ibuprofen
Extreme care must be taken to ensure that intentional or unintentional overdoses do not take place. Due to the risk of overdose associated with paracetamol and aspirin, pack sizes are restricted for OTC purchase. Patients should be reminded that many OTC preparations contain paracetamol, e.g. cold and flu preparations, and that the maximum daily dose must be adhered to. Paracetamol overdose leads to nausea, vomiting and eventually hepatic failure, which is often not apparent for four to six days.
Paracetamol dose instructions for children are based on narrow age bands to ensure more accurate dosing at home (as it is not practical for parents or carers to calculate a dose based on mg/kg bodyweight). Pharmacists should advise accordingly and point out the dosing recommendations to parents. The association of aspirin with Reye’s syndrome (a potentially fatal neurological condition in children) has led to restriction in the use of aspirin, to adults and children aged 16 years and over.
Both aspirin and ibuprofen should be avoided during pregnancy, particularly during the third trimester because of possible bleeding with aspirin and prolongation of pregnancy with both drugs. Paracetamol is safe for use in pregnancy and breastfeeding.
Paracetamol is the only option for patients with a history of hypersensitivity to aspirin or NSAIDs or active peptic ulceration. Haemophiliacs should not be given aspirin. Patients receiving oral anticoagulants, methotrexate or thiazides are also best treated with paracetamol if an analgesic is required, to avoid dosage adjustments. Aspirin has marked anti-platelet activity, which persists for several days. While ibuprofen exerts some anti-platelet effect, it only lasts for a few hours. NSAIDs may provoke renal failure, especially in patients with renal, cardiac or hepatic impairment or in conjunction with diuretics or ACE inhibitors. Paracetamol is the analgesia of choice in these cases.
Aspirin may precipitate attacks in as many as one in 20 patients with asthma and there is some degree of cross-reactivity with ibuprofen but with lower incidence. Neither drug should be used in patients with asthma if previous use has caused problems. They should be used with extreme caution in people not previously exposed to aspirin or ibuprofen. In overdose, ibuprofen is safer than aspirin. Both are associated with adverse gastro-intestinal (GI) effects but ibuprofen has a lower incidence. GI effects are minimised by taking the drugs after food. Paracetamol is less irritant to the stomach and so is often preferred, particularly in the elderly.
Codeine and dihydrocodeine are available OTC in combination with other analgesics. Combination analgesics are not routinely recommended as they remove the flexibility of titrating the dose of each drug individually. They may be a useful option for pain relief if a patient is likely to become confused with two separate analgesics and one agent alone does not provide relief. The low dose of opioid (8mg codeine) that is contained in the majority of OTC compound preparations is not enough to provide significant pain relief. The therapeutic analgesic dose of codeine is 30mg. At sub-therapeutic doses it will cause opioid side effects, in particular, constipation, especially in the elderly. Higher doses of opioid analgesics are associated with a risk of dependence and misuse, either intentional or unintentional.
Caffeine is a weak stimulant which, when included in analgesic preparations, is claimed to enhance the analgesic effect. Side effects include nausea, headache and insomnia. There is also the risk of a habit-forming effect.
