Pholcodine

Pholcodine may enhance the sedative effect of central nervous system depressants including alcohol, barbiturates, hypnotics, narcotic analgesics, sedatives and tranquillisers (phenothiazines and tricyclic antidepressants).

The reduction in blood pressure caused by antihypertensives may accentuate the hypotensive effects of pholcodine. Diuretics may have the same effect.

Interaction with neuromuscular blocking agents (anaphylaxis) has been reported.

Severe cutaneous adverse reactions (SCARs) including acute generalized exanthematous pustulosis (AGEP), which can be life-threatening or fatal, have been reported in patients treated with pholcodine-containing products, most likely in the first week. Patients should be advised of the signs and symptoms and monitored closely for skin reactions. If signs and symptoms suggestive of these reactions appear, pholcodine should be withdrawn immediately.

The safety of pholcodine during pregnancy has not been established. Based on the available data for morphine, it would seem likely that use of pholcodine during pregnancy would not be associated with congenital defects. However, its use should be carefully assessed by consideration of small benefits versus potential risk to the foetus.

The safety of pholcodine during lactation has not been established. Based on the available data for morphine, it would seem likely that use of pholcodine during lactation would not be contraindicated. However, its use should be carefully assessed by consideration of small benefits versus potential risk to the neonate.

This medicine can impair cognitive function and can affect a patient’s ability to drive safely. This class of medicine is in the list of drugs included in regulations under 5a of the Road Traffic Act 1988. When prescribing this medicine, patients should be told:

• The medicine is likely to affect your ability to drive.
• Do not drive until you know how the medicine affects you.
• It is an offence to drive while under the influence of this medicine.
• However, you would not be committing an offence (called a ‘statutory defence’) if:
  • The medicine has been prescribed to treat a medical or dental problem and
  • You have taken it according to the instructions given by the prescriber and in the information provided with the medicine and
  • It was not affecting your ability to drive safely.

The following side effects may be associated with the use of pholcodine: Occasional drowsiness, dizziness, excitation, confusion, sputum retention, vomiting, gastrointestinal disturbances (nausea and constipation).

Skin and subcutaneous tissue disorders: Skin reactions including rash.

Acute generalized exanthematous pustulosis (frequency unknown).

Immune system disorders have been noted including hypersensitivity reactions and anaphylaxis.