Pethidine

Registered South African indications:

• Pain

Contraindications

• Hypersensitivity to active ingredient or to any of the excipients
• Severe renal impairment
• Severe hepatic impairment
• Severe respiratory depression
• Severe obstructive airways disease or severe asthma
• Supraventricular tachycardia
• Delirium tremens
• Raised intracranial pressure
• Head injuries
• Comatose patients
• Convulsive states such as status epilepticus
• Patients with a risk of paralytic ileus
• Acute alcoholism
• Use of pethidine in patients with phaeochromocytoma may result in hypertensive crisis
• Use of pethidine should be avoided in patients with diabetic acidosis where there is danger of coma
• Coadministration with monoamine oxidase inhibitors (including moclobemide, and the monoamine B inhibitors selegiline and rasagiline) or within two weeks of their withdrawal
• Coadministration with ritonavir

Cautions

• Pregnancy
• Breastfeeding
• Mild to moderate renal impairment
• Mild to moderate hepatic impairment
• Elderly 
• Acute or chronic airflow obstruction
• History of convulsive disorders
• Hypotension
• Shock
• Adrenocortical insufficiency
• Hypothyroidism
• Prostatic hypertrophy
• Biliary tract disorders
• Severe inflammatory bowel disease
• Acute abdominal conditions  
• Myasthenia gravis
• Neonates
• Debilitated patients
• Sickle cell anaemia
• Pheochromocytoma
• Toxic psychosis
• May impair ability to drive and operate machinery

Forms avail. in SA and covered in this monograph: Inj

Acute pain - moderate to severe

• IM/IV/SC: 50-150mg, 3-4hrly; Max:150mg/dose; Max: 600mg/24hrs.
• IM: 1-1,5mg/kg/dose; Max 150mg/dose; Max: 600mg/24hrs

Active labour

• IM/SC: 50-100mg; Initiate once pain experienced as soon as contractions occur; Repeat at intervals of 1-3hrs; Max: 400mg/24hrs 

Preoperative - premedication 

• IM: 50-100mg, 30-90min before operation  

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Adjust and titrate doses to individual analgesic requirements

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Expert note: IM dose is preferred in clinical practice due to more predictable uptake and onset; SC route is rarely used in routine clinical practice in SA

Paed. forms avail. in SA and covered in this monograph: Inj

Acute pain - moderate to severe

• IM: 0.5-2mg/kg/dose 4hrly; Max: 100mg/dose

Premedication - preoperative

• IM: 1-2mg/kg/dose, 30-90min before operation;Max: 100mg/dose

Pregnancy

• Caution
• There is inadequate evidence of safety in human pregnancy, but pethidine has been in widespread use for many years without apparent ill consequence. Animal studies have not shown any hazard
• As with all medicines during pregnancy care should be taken in assessing the risk to benefit ratio. Administration during labour may cause respiratory depression in the newborn infant

Breastfeeding

• Caution; not recommended
• Pethidine is excreted in breast milk. Patients should be advised to discontinue breastfeeding during treatment with pethidine

Renal Impairment

• Mild to moderate: Caution; dose adjustment recommended
• Severe: Contraindicated

eGFR (ml/min)	Dose
≥50- 89	Reduce dose by 25%
≥30- 49	Reduce dose by 50% (limit use to acute severe pain and when an alternative potent analgesic is not accessible)
Established (ESRD) renal impairment	Contraindicated

Hepatic Impairment 

• Mild to moderate: Caution; no dose adjustment recommended
  Consider initiating at lower end of dosage range
• Severe: Contraindicated

Elderly

• Caution; dose adjustment recommended
  Initial doses should not exceed 25mg

Porphyria Information

• Not porphyrinogenic (NP)

Drugs in Sport

• Prohibited - In competition

Central Nervous System Disorders

• Dependence
• Confusion
• Mood altered
• Euphoria
• Hallucinations
• Dysphoria
• Drowsiness
• Dizziness
• Tremor
• Convulsions
• Headache
• Fainting
• Tolerance

Cardiovascular disorders

• Tachycardia
• Bradycardia
• Palpitations
• Flushing
• Hypotension
• Hypertension

Respiratory Disorders

• Respiratory depression
• Bronchoconstriction

Gastrointestinal Disorders

• Nausea and vomiting
• Dry mouth
• Constipation
• Slowed gastric emptying

Hepatobiliary Disorders

• Biliary spasm

Genitourinary System Disorders

• Sexual dysfunction
• Difficulty in micturition
• Renal colic

Musculoskeletal Disorders

• Muscle twitching

Skin and Subcutaneous Tissue Disorders

• Sweating
• Rash
• Urticaria
• Pruritus

Immune, Blood and Lymphatic System Disorders

• Hypersensitivity

Sensory Disorders

• Dry eye
• Miosis
• Corneal reflex decreased
• Vertigo

Others

• Hypothermia
• Injection site reactions

• Monoamine oxidase inhibitors
• Moclobemide
• Monoamine B inhibitors
• Selegiline
• Rasagiline
• Ritonavir
• Central nervous system depressant agents
• Antipsychotics 
• Opioid agonists 
• Anticonvulsants
• Antiviral
• Histamine H2 antagonists
• Domperidone
• Ciprofloxacin
• Serotonergic agents

None routine. Specific cases may require

• Respiratory function
• Cardiovascular function
• Renal function
• Liver function

Pethidine is a mu receptor agonist. It exerts its main pharmacological action on the central nervous system.

Injection (per ml) 25mg

• Pethidine HCI Fresenius (Fresenius)
• Pharma-Q Pethidine (Pharma-Q)

Injection (per ml) 50mg

• Pethidine HCI Fresenius (Fresenius)
• Pharma-Q Pethidine (Pharma-Q)
• Sabax Pethidine (Adcock) originator

Injection (per ml)100mg

• Pethidine HCI Fresenius (Fresenius)
• Pharma-Q Pethidine (Pharma-Q)