Drugs List

Therapeutic Indications

Uses

For the relief of moderate to severe pain.

Administration

For oral administration

Pentazocine should be administered with or after food.

Contraindications

Raised intracranial pressure
Head trauma
Coma
Brain disorder - where clouding of the sensorium is undesirable
Acute alcohol intoxication

Porphyria

Respiratory depression
Acute asthma
Cardiac failure secondary to chronic lung disease

Children under 6 years of age

Within 2 weeks of discontinuing MAOIs

Precautions and Warnings

Opioid dependence or patients taking other opiates. Pentazocine has both agonist and antagonist properties and as such may precipitate withdrawal reactions or pain in patients taking other opioids.

Renal impairment
Hepatic impairment

Pregnancy (see Pregnancy)
Breastfeeding (see Lactation)

Elderly - reduce dose
Children under 12 years - only the 25mg tablets are licensed for this age group

Recent myocardial infarction - pentazocine may increase heart rate and blood pressure
Cardiac arrhythmias

Phaeochromocytoma - pentazocine may increase heart rate and blood pressure
Adrenocortical insufficiency

Seizures

Hypothyroidism

Inflammatory bowel disorders
Obstructive bowel disorders

Prostate disorders - Prostatic hypertrophy

Patients should be advised to avoid alcohol during treatment with pentazocine

Patients should be advised that their ability to drive and operate machinery may be compromised during treatment

Some formulations contain lactose, caution in galactosaemia, glucose-galactose malabsorption syndrome and lactose intolerance.

Use in Porphyria

Pregnancy and Lactation

Pregnancy

Use with caution in pregnancy. There is no epidemiological evidence for the safety of pentazocine in human pregnancy, but it has been widely used for many years without apparent ill consequences.

Pentazocine crosses the placenta and into the foetal circulation. Opioid effects including central depression and abstinence syndrome may be seen in the foetus and newborn. It does not appear to have significant adverse effects on uterine function at parturition.

Animal studies showed harmful effects in foetal rodents but only at doses which also produced maternal toxicity.

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14-17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Use with caution in lactation.

Pentazocine is excreted in small amounts in breast milk so it is recommended that infants of nursing mothers receiving high doses of pentazocine be appropriately monitored.

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Sedation
Nausea
Diaphoresis
Flushing
Visual disturbances
Vomiting
Dry mouth
Constipation
Nightmares
Paraesthesia
Respiratory depression
Dysphoria
Hallucinations
Dizziness
Lightheadedness
Headache
Tachycardia
Mood changes
Pruritus
Biliary spasm
Urinary retention
Hypotension
Hypertension (transient)
Altered uterine contractions
Tremor
Insomnia
Disorientation
Chills
Allergic reaction
Toxic epidermal necrolysis
Bradycardia
Circulatory depression
Palpitations
Syncope
Euphoria
Convulsions
Raised intracranial pressure
Confusion
Oedema
Rash
Urticaria
Dermatitis
Miosis
Hypothermia
Reduced libido
Facial oedema
Myalgia
Blood disorders
Abdominal pain
Ureteric spasm

Presentation

Tablets containing 25mg pentazocine hydrochloride
Capsules containing 50mg pentazocine hydrochloride

Drugs List

Therapeutic Indications

Uses

For the relief of moderate to severe pain.

Dosage

Adults

Elderly

Children

Patients with Renal Impairment

Patients with Hepatic Impairment

Administration

For oral administration

Pentazocine should be administered with or after food.

Contraindications

Raised intracranial pressure
Head trauma
Coma
Brain disorder - where clouding of the sensorium is undesirable
Acute alcohol intoxication

Porphyria

Respiratory depression
Acute asthma
Cardiac failure secondary to chronic lung disease

Children under 6 years of age

Within 2 weeks of discontinuing MAOIs

Precautions and Warnings

Opioid dependence or patients taking other opiates. Pentazocine has both agonist and antagonist properties and as such may precipitate withdrawal reactions or pain in patients taking other opioids.

Renal impairment
Hepatic impairment

Pregnancy (see Pregnancy)
Breastfeeding (see Lactation)

Elderly - reduce dose
Children under 12 years - only the 25mg tablets are licensed for this age group

Recent myocardial infarction - pentazocine may increase heart rate and blood pressure
Cardiac arrhythmias

Phaeochromocytoma - pentazocine may increase heart rate and blood pressure
Adrenocortical insufficiency

Seizures

Hypothyroidism

Inflammatory bowel disorders
Obstructive bowel disorders

Prostate disorders - Prostatic hypertrophy

Patients should be advised to avoid alcohol during treatment with pentazocine

Patients should be advised that their ability to drive and operate machinery may be compromised during treatment

Some formulations contain lactose, caution in galactosaemia, glucose-galactose malabsorption syndrome and lactose intolerance.

Use in Porphyria

Pregnancy and Lactation

Pregnancy

Use with caution in pregnancy. There is no epidemiological evidence for the safety of pentazocine in human pregnancy, but it has been widely used for many years without apparent ill consequences.

Pentazocine crosses the placenta and into the foetal circulation. Opioid effects including central depression and abstinence syndrome may be seen in the foetus and newborn. It does not appear to have significant adverse effects on uterine function at parturition.

Animal studies showed harmful effects in foetal rodents but only at doses which also produced maternal toxicity.

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14-17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Use with caution in lactation.

Pentazocine is excreted in small amounts in breast milk so it is recommended that infants of nursing mothers receiving high doses of pentazocine be appropriately monitored.

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Effects on Ability to Drive and Operate Machinery

This class of medicine is in the list of drugs included in regulations under 5a of the Road Traffic Act 1988 (England and Wales). When prescribing this medicine: Advise patient the medicine can affect cognitive function and is likely to affect ability to drive. Advise patient not to drive until they know how the medicine affects them.

Counselling

Patients should be advised to avoid alcohol during treatment with pentazocine

Patients should be advised that their ability to drive and operate machinery may be compromised during treatment

Side Effects

Sedation
Nausea
Diaphoresis
Flushing
Visual disturbances
Vomiting
Dry mouth
Constipation
Nightmares
Paraesthesia
Respiratory depression
Dysphoria
Hallucinations
Dizziness
Lightheadedness
Headache
Tachycardia
Mood changes
Pruritus
Biliary spasm
Urinary retention
Hypotension
Hypertension (transient)
Altered uterine contractions
Tremor
Insomnia
Disorientation
Chills
Allergic reaction
Toxic epidermal necrolysis
Bradycardia
Circulatory depression
Palpitations
Syncope
Euphoria
Convulsions
Raised intracranial pressure
Confusion
Oedema
Rash
Urticaria
Dermatitis
Miosis
Hypothermia
Reduced libido
Facial oedema
Myalgia
Blood disorders
Abdominal pain
Ureteric spasm

Overdosage

It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

The following number will direct the caller to the relevant local centre (0844) 892 0111

Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Shelf Life and Storage

Store below 25 degrees C
Protect from light
Store in a dry place

Reference Sources

British National Formulary, 62nd Edition (2011) Pharmaceutical Press, London.

BNF for Children (2011-2012) Pharmaceutical Press, London.

Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 9th edition (2011) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

Martindale: The Complete Drug Reference, 37th edition (2011) ed. Sweetman, S. Pharmaceutical Press, London.

Summary of Product Characteristics: Pentazocine 25mg Tablets, Actavis. Revised July 2011

Summary of Product Characteristics: Pentazocine 50mg Capsules, Actavis. Revised July 2011

US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
Available at: https://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT
Pentazocine Last revised: January 4, 2011
Last accessed: February 1, 2012

Gov.uk. Government departments. Department for Transport. Publications. Drug driving and medicine: advice for healthcare professionals. Drug driving: Guidance for healthcare professionals on drug driving. Available at: https://www.gov.uk Last accessed: 6 January 2015 New drug driving offence implications for medicines packaging. Medicines Regulatory News. 10 December 2013. Available at: https://www.mhra.gov.uk Last accessed: 6 January 2015