CODEINE PHOSPHATE

Codeine Phosphate Tablets 15 mg are not indicated for children 0-18 years old. Codeine should be used at the lowest effective dose for the shortest period of time. This dose may be taken, up to 4 times a day at intervals of not less than 6 hours.

Maximum daily dose of codeine should not exceed 240 mg.

In mild to moderate pain:

Adults and the elderly: 30 mg to 60 mg every 6 hours when necessary, to a maximum of 180 mg daily.

As an anti-tussive:

Adults and the elderly: 15 mg to 30 mg, 3 or 4 times daily.

For the symptomatic treatment of chronic diarrhoea:

Adults and the elderly: 15 mg to 60 mg every 6 hours, to a maximum of 180 mg daily. The duration of treatment should be limited to 3 days and if no effective pain relief is achieved the patients/carers should be advised to seek the views of a physician.

Method of administration:

Oral

Constipation, tolerance, dependence, sedation, dizziness, and nausea may occur; may enhance the effect of alcohol. Rash, urticaria, pruritus and headache have also been reported. Regular prolonged use of codeine/ DHC is known to lead to addiction and tolerance.

Symptoms of restlessness and irritability may result when treatment is stopped. Prolonged use of painkiller for headaches can make them worse.

Prolonged use of high doses has produced morphine-like dependency. Avoid when there is a history of asthma, hepatic or renal impairment, or of drug abuse. The risk benefit of continued use should be assessed regularly by the prescriber.

CYP2D6 metabolism Codeine is metabolised by the liver enzyme CYP2D6 into morphine, its active metabolite. If a patient has a deficiency or is completely lacking this enzyme an adequate analgesic effect will not be obtained. Estimates indicate that up to 7% of the Caucasian population may have this deficiency.

However, if the patient is an extensive or ultra-rapid metaboliser there is an increased risk of developing side effects of opioid toxicity even at commonly prescribed doses. These patients convert codeine into morphine rapidly resulting in higher than expected serum morphine levels.

General symptoms of opioid toxicity include confusion, somnolence, shallow breathing, small pupils, nausea, vomiting, constipation and lack of appetite. In severe cases this may include symptoms of circulatory and respiratory depression, which may be life-threatening and very rarely fatal.

9% Nothern European 1% to 2% Risk from concomitant use of sedative medicines such as benzodiazepines or related drugs: Concomitant use of Codeine and sedative medicines such as benzodiazepines or related drugs may result in sedation, respiratory depression, coma and death.

Because of these risks, concomitant prescribing with these sedative medicines should be reserved for patients for whom alternative treatment options are not possible. If a decision is made to prescribe Codeine concomitantly with sedative medicines, the lowest effective dose should be used, and the duration of treatment should be as short as possible.

The patients should be followed closely for signs and symptoms of respiratory depression and sedation. 5).

• Respiratory depression and liver failure. 4). 6). • In patients for whom it is known they are CYP2D6 ultra-rapid metabolisers.