Formulary
Pentazocine: Indications, Dosing, Side Effects and Interactions
Pentazocine clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 4 min read
Pentazocine: Indications, Dosing, Side Effects and Interactions
Pentazocine clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Moderate to severe pain**
- **Adult** (By Mouth): 50 mg every 3-4 hours, dose to be taken preferably after food, usual dose 25-100 mg every 3-4 hours; maximum 600 mg per day.
**Moderate pain**
- **Adult** (By Subcutaneous Injection, Or By Intramuscular Injection, Or By Intravenous Injection): 30 mg every 3-4 hours as required; maximum 360 mg per day.
**Severe pain**
- **Adult** (By Subcutaneous Injection, Or By Intramuscular Injection, Or By Intravenous Injection): 45-60 mg every 3-4 hours as required; maximum 360 mg per day.
Cautions
Adrenocortical insufficiency (reduced dose is recommended); asthma (avoid during an acute attack); central sleep apnoea; convulsive disorders; current or history of mental health disorder; current or history of substance use disorder; debilitated patients (reduced dose is recommended); diseases of the biliary tract; elderly (reduced dose is recommended); hypotension; hypothyroidism (reduced dose is recommended); impaired respiratory function (avoid in chronic obstructive pulmonary disease); inflammatory bowel disorders; myasthenia gravis; obstructive bowel disorders; prostatic hypertrophy; shock; urethral stenosis Cautions, further information Dependence and addiction Prolonged use of opioid analgesics may lead to drug dependence and addiction, even at therapeutic doses. There is an increased risk in individuals with current or history of substance use disorder or mental health disorders. See also Important safety information . Central sleep apnoea Opioids cause a dose-dependent increased risk of central sleep apnoea, consider total opioid dose reduction. M Palliative care In the control of pain in terminal illness, the cautions listed should not necessarily be a deterrent to the use of opioid analgesics. M Elderly Screening Tool of Older Persons' potentially inappropriate Prescriptions (STOPP) criteria to aid medication reviews (see Prescribing in the elderly for information). Potentially inappropriate: if prescribed a strong , oral , or transdermal opioid (i.e. morphine, oxycodone, fentanyl, buprenorphine, diamorphine, methadone, tramadol, pethidine, pentazocine) as first-line therapy for mild pain (WHO analgesic ladder not observed) if used regularly without concomitant laxative (risk of severe constipation) if prescribed a long-acting (modified-release) opioid without a short-acting (immediate-release) opioid for breakthrough pain (risk of persistence of severe pain) Cautions For pentazocine Arterial hypertension; cardiac arrhythmias; myocardial infarction; pancreatitis; phaeochromocytoma; pulmonary hypertension
Contraindications
Acute respiratory depression; comatose patients; head injury (opioid analgesics interfere with pupillary responses vital for neurological assessment); raised intracranial pressure (opioid analgesics interfere with pupillary responses vital for neurological assessment); risk of paralytic ileus Contra-indications For pentazocine Acute porphyrias ; heart failure secondary to chronic lung disease; patients dependent on opioids (can precipitate withdrawal)
Side effects
Common or very common Arrhythmias; confusion; constipation; dizziness; drowsiness; dry mouth; euphoric mood; flushing; hallucination; headache; hyperhidrosis; hypotension (with high doses); miosis; nausea (more common on initiation); palpitations; respiratory depression (with high doses); skin reactions; urinary retention; vertigo; visual impairment; vomiting (more common on initiation); withdrawal syndrome Uncommon Drug dependence; dysphoria; seizure Side-effects, further information Respiratory depression Respiratory depression is a major concern with opioid analgesics and it may be treated by artificial ventilation or be reversed by naloxone. Dependence, addiction, and withdrawal Long term use of opioids in non-malignant pain (longer than 3 months) carries an increased risk of dependence and addiction, even at therapeutic doses. At the end of treatment the dosage should be tapered slowly to reduce the risk of withdrawal effects; tapering from a high dose may take weeks or months. See also Important safety information . Overdose Opioids (narcotic analgesics) cause coma, respiratory depression, and pinpoint pupils. For details on the management of poisoning, see Opioids, under Emergency treatment of poisoning and consider the specific antidote, naloxone hydrochloride. Side-effects For pentazocine Frequency not known Biliary spasm; blood disorder; chills; circulatory depression; face oedema; facial plethora; generalised tonic-clonic seizure; hypertension; hypothermia; intracranial pressure increased; mood altered; myalgia; paraesthesia; sexual dysfunction; sleep disorders; syncope; toxic epidermal necrolysis; tremor; ureteral spasm Overdose Effects only partially reversed by naloxone.
Interactions
**Other interactions (2):**
- John's Wort [ Hypericum perforatum ], opioids [e.g., fentanyl and its analogues, tramadol, dextromethorphan, tapentadol, pethidine, methadone, pentazocine, buprenorphine and buprenorphine/naloxone...
- The same interactions with MAO inhibitors cannot be ruled out during treatment with tramadol.
Pregnancy
Respiratory depression and withdrawal symptoms can occur in the neonate if opioid analgesics are used during delivery; also gastric stasis and inhalation pneumonia has been reported in the mother if opioid analgesics are used during labour.
Breast feeding
Use with caution-limited information available.
Hepatic impairment
Caution in severe impairment (risk of increased bioavailability). M Dose adjustments Reduce dose in severe impairment. M
Renal impairment
Use with caution in severe impairment. M Dose adjustments Reduce dose in severe impairment (risk of increased and prolonged effects). M
Medicinal forms
Tablet,Capsule
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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