Dihydrocodeine

Dihydrocodeine is an opioid analgesic . It is used for the relief of moderate to severe pain, often in combination preparations with paracetamol. It has also been used as a cough suppressant.

Generic Name 藥名	HA Code 藥物代碼	Classification藥物分類
Dihydrocoedine	DIHY01	DD

Mechanism of Action

Equivalent doses of opioid analgesics

Analgesic/Route	Dose
Codeine: PO	100 mg
Diamorphine: IM, IV, SC	3 mg
Dihydrocodeine: PO	100 mg
Morphine: PO	10 mg
Morphine: IM, IV, SC	5 mg
Oxycodone: PO	6.6 mg
Tramadol: PO	100 mg

Route of Administration	PO (tablet form)

Dosage

Moderate to severe pain:

Oral	30mg after food every 4 to 6 hours; up to 240mg daily.
	Modified-release preparations are taken twice daily.
Subcutaneous or intramuscular	50 mg every 4 to 6 hours.

Doses in children:

• may be given orally, or by deep subcutaneous or intramuscular injection;

1 to 3 years: 500 micrograms/kg every 4 to 6 hours

4 to 12 years: 0.5 to 1 mg/kg every 4 to 6 hours

Older children may be given the usual adult dose.

Side Effects

As for Opioid Analgesic in general

The commonest adverse effects are nausea, vomiting, constipation, drowsiness and confusion.

Large doses of opioids produce respiratory depression and hypotension, with circulatory failure and deepening coma. Death may occur from respiratory failure.

Treatment of Adverse Effects

Abdominal pain, hyperthermia, pancreatitis Euphoria, nausea and vomiting, respiratory depression, constipation and cough suppression.

Pharmacokinetics

Oral bioavailability	Oral bioavailability is only about 20%, probably because of substantial first-pass metabolism in the gut wall or liver.
Onset of action	peak concentrations of dihydrocodeine occur about 1.2 to 1.8 hours after oral doses.
Metabolism	Dihydrocodeine is metabolized in the liver, and is excreted in urine.
Elimination half-life	Elimination half-life is reported to range from about 3.5 to 5 hours.