Buprenorphine

Introduction

Buprenorphine is an opioid analgesic. It is used for the relief of moderate to severe pain and as an adjunct to anaesthesia. It is also used in the treatment of opioid dependence.

Transdermal buprenorphine patches is used for chronic intractable cancer pain and neuropathic pain. However, this route is not suitable for the treatment of acute pain.

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

Mechanism of Action

Pain relief

opioid dependence

Route of Administration	IV

Dosage

For chronic moderate to severe pain

Intramuscular : analgesia is apparent within 15 minutes and lasts up to 6 hours.

A slower, more prolonged response is achieved after sublingual doses. The analgesic effects of buprenorphine after transdermal application may not be seen for at least 12 to 24 hours.

Buprenorphine is given by all the above routes for relief of moderate and severe pain.

• Intramuscular or slow intravenous : 300 to 600 micrograms every 6 to 8 hours as required.
• Transmucosal : sublingual doses of 200 to 400 micrograms every 6 to 8 hours as required.
• Transdermal patches : doses should be individually titrated according to previous opioid usage. Patches are not appropriate for acute pain.

Use of a patch providing 35 micrograms/hour of buprenorphine is roughly equivalent to 30 to 60 mg daily of oral morphine sulphate.

For the treatment of opioid dependence , buprenorphine is given by the oral transmucosal route,

Sublingually : the initial dose is 0.8 to 4 mg once daily. The dose may be increased as necessary but maintenance doses should not exceed 32 mg daily.

Moderate to severe pain: 200-400 mcg q6-8h PRN

Opioid dependence: nitially 0.8-4mg on first day, usual dose 12-24mg QD, max 32mg

Doses in children

Intramuscular or slow intravenous : 6 months to 12 years: 3 to 6 micrograms/kg every 6 to 8 hours; up to 9 micrograms/kg if required in refractory cases.

Sublingual route is licensed in children aged from 6 to 12 years:

• 16 to 25 kg: 100 micrograms
• 25 to 37.5 kg: 100 to 200 micrograms
• 37.5 to 50 kg: 200 to 300 micrograms

Older children may be given the usual adult dose.

Side Effects

Local reactions such as rash, erythema and itching have been reported with the transdermal patches.

Anoreia, anxiety, asthenia, diarrhea, dyspnea, mild opioid withdrawal symptom

Pharmacokinetics

Bioavailability	Oral absorption takes place through the buccal mucosa after sublingual doses
	Transdermal application results in absorption through the skin;
Onset of action	Oral peak plasma concentrations occur after 90 minutes.
	The minimum effective concentration is reached in 12 to 24 hours and peak plasma concentrations occur after about 60 hours.
Metabolism	Buprenorphine is subject to considerable first-pass metabolism after oral doses.
Elimination half-life	Plasma elimination half-lives have ranged from 1.2 to 7.2 hours after intravenous injection; elimination half-lives after sublingual or transdermal use are longer and may range from 20 to 36 hours or more.

Drug Management

Efficiency

Pain control, opioid withdrawal symptom

Safety

mental status, blood pressure, respiratory drive

Precautions

absorption of buprenorphine from transdermal patches may be increased as the temperature rises. Patients with fever may require monitoring because of increased absorption. It may take up to 30 hours for plasma concentrations of buprenorphine to decrease by 50% after removal of a patch; patients who have had adverse effects should be monitored during this period. It is recommended that transdermal buprenorphine should be avoided in patients with history of QT interval prolongation and used with caution in those with hypokalaemia or unstable cardiac disease such as atrial fibrillation, congestive heart failure, or myocardial ischaemia.

Caution

Impaired conciouness, Concomitant use of hepatotoxic medication Tolerance and dependence

FAQ

What should I avoid while taking?

Avoid abrupt withdrawal