Diazepam Flashcards
What is diazepam?
Benzodiazepine with anticonvulsant, anxiolytic, sedative, muscle relaxant, and amnesic properties and a long duration of action
What is diazepam indicated for?
- severe anxiety disorders,
- hypnotic in the short-term management of insomnia,
- sedative and premedicant,
- anticonvulsant,
- management of alcohol withdrawal syndrome.
What is the role of therapy of diazepam in epilepsy?
Used in the treatment of status epilepticus if buccal midazolam fails
Rectal: Adult 10–20 mg, repeated once after 10–15 minutes if necessary; elderly 10 mg repeated once after 10–15 minutes if necessary
IV: Adult 10 mg at a rate of 5 mg per minute, repeated once after 10 minutes if necessary
What are the relevant PK/PD parameters of diazepam?
Diazepam acts on parts of the limbic system, the thalamus and hypothalamus, and induces calming effects, but has no demonstrable peripheral autonomic blocking action, nor does it produce extrapyramidal side effects
93% bioavailability
undergoes hepatic metabolism
Biphasic half life of 1-2 days and 2-5 days.
excreted via urine.
What is the mechanism of action of diazepam?
bind nonspecifically to benzodiazepine receptors which mediate sleep, muscle relaxation, anticonvulsant activity, motor coordination, and memory.
As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABAA) receptors, this enhances the effects of GABA by affinity of the GABA receptor, which indirectly opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell.
What are the precautions of diazepam?
respiratory disease, muscle weakness and myasthenia gravis, organic changes history of drug or alcohol dependence personality disorder increases risk of dependence reduce dose in elderly and debilitated avoid prolonged use observe closely if given parenterally observe respiratory activity if giving IV Pregnancy class C. Compatible with breastfeeding but take care with chronic use and monitor infant for drowsiness
What are the contraindications
respiratory depression marked neuromusclar respiratory weakness incl. unstable myasthenia gravis acute pulmonary insufficiency sleep apnoea syndrome chronic psychosis phobiv/obsessional states hyperkinesis, monotherapy in depression/anxiety with depression acute angle closure glaucoma hepaitc impairment renal impairment
What are the adverse effects with diazepam?
drowsiness and light headedness the following day,
confusion and ataxia (esp. in elderly)
amnesia, dependence, paradoxical increasedaggression
muscle weakness.
Less commonly: headache, vertigo, dizzienss, slurred speech, hypotension, salivation changes, GI distrubances, visual disturbances,
What are the drug interactions with diazepam?
Indinavir predicted to increase diazepam exposure which increases risk of prolonged sedation and respiratory depression
Methodone can result in benefiical analgeisc effects as well as enhanced sedation and respiratory depression.
Rifampicin moderately decreases diazepam exposure
Ritonavir may increase diazepam exposure
Concurrent use with TCA and benzodiazepinen normally uneventful but some cases of drowsiness and incoordination following use of combination have been reported
What are the alarm bells with diazepam use?
Report behavioural changes incl suicidality and depression to doctor immediately.
Avoid alcohol.
What class of drugs does diazepam belong to?
anticonvulsants
What are other drugs in the same class as diazepam?
Primidone Gabapentin Topiramate Phenytoin Acetaazolamide Clobazam Lamotrigine Clonazepam Levetiracetam
