Diamorphine hydrochloride
CLINICAL USE
Opiate analgesic:Control of severe pain Pain relief in myocardial infarction (MI) Acute pulmonary oedema
DOSE IN NORMAL RENAL FUNCTION
Severe pain: Oral/SC/IM: 5–10 mg 4 hourly, increasing dose as necessaryAcute MI, pulmonary oedema: IV: 2.5–5 mg. Elderly patients – reduce dose by half
PHARMACOKINETICS
DOSE IN RENAL IMPAIRMENT
GFR (mL/MIN)
DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES
IMPORTANT DRUG INTERACTIONS
Potentially hazardous interactions with other drugsAnti-arrhythmics: delayed absorption of mexiletineAntidepressants: possible CNS excitation or depression with MAOIs – avoid concomitant use and for 2 weeks after stopping MAOI; possible CNS excitation or depression with moclobemide; increased sedative effects with tricyclicsAntipsychotics: enhanced sedative and hypotensive effectSodium oxybate: enhanced effect of sodium oxybate – avoid concomitant use
ADMINISTRATION
Reconstition
1 mL water for injection or sodium chloride 0.9% (less may be used, e.g. for SC injection use 0.1 mL for 10 mg)
Route
IV, IM, SC, oral
Rate of Administration
IV: 1 mg/minute
Comments
Monitor BP and respiratory rates
OTHER INFORMATION
Increased cerebral sensitivity in renal impairment which can result in excessive sedation and serious respiratory depression necessitating ventilationMore rapid onset and shorter duration of action than morphineExtreme caution with regular dosing – accumulation of active metabolites may occurNaloxone must be readily available for reversal if required