indication

For the treatment of insomnia.

pharmacology

Butethal (also known as butobarbitone and butobarbital) belongs to a group of medicines called the barbiturates. It is thought to act on receptors in the brain (GABA receptors) causing the release of the chemical GABA. This chemical inhibits certain areas of the brain resulting in sleepiness.

mechanism of action

Butethal binds at a distinct binding site associated with a Cl^- ionopore at the GABA_A receptor, increasing the duration of time for which the Cl^- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged. All of these effects are associated with marked decreases in GABA-sensitive neuronal calcium conductance (gCa). The net result of barbiturate action is acute potentiation of inhibitory GABAergic tone. Barbiturates also act through potent (if less well characterized) and direct inhibition of excitatory AMPA-type glutamate receptors, resulting in a profound suppression of glutamatergic neurotransmission.

toxicity

Signs of overdose include confusion (severe), decrease in or loss of reflexes, drowsiness (severe), fever, irritability (continuing), low body temperature, poor judgment, shortness of breath or slow or troubled breathing, slow heartbeat, slurred speech, staggering, trouble in sleeping, unusual movements of the eyes, weakness (severe).

biotransformation

Hepatic.

absorption

Rapidly absorbed following oral administration.

half life

37 hours

drug interactions

Aminophylline: The barbiturate, butethal, decreases the effect of aminophylline.

Betamethasone: The barbiturate, butethal, may decrease the effect of the corticosteroid, betamethasone.

Clomifene: The enzyme inducer, butethal, decreases the effect of the hormone agent, clomifene.

Conjugated Estrogens: The enzyme inducer, butethal, decreases the effect of the hormone agent, conjugated estrogens.

Cyclosporine: The barbiturate, butethal, increases the effect of cyclosporine.

Dexamethasone: The barbiturate, butethal, may decrease the effect of the corticosteroid, dexamethasone.

Diethylstilbestrol: The enzyme inducer, butethal, decreases the effect of the hormone agent, diethylstilbestrol.

Doxycycline: The anticonvulsant, butethal, decreases the effect of doxycycline.

Estradiol: The enzyme inducer, butethal, decreases the effect of the hormone agent, estradiol.

Ethinyl Estradiol: This product may cause a slight decrease of contraceptive effect

Felodipine: The barbiturate, butethal, decreases the effect of felodipine.

Fludrocortisone: The barbiturate, butethal, may decrease the effect of the corticosteroid, fludrocortisone.

Folic Acid: Folic acid decreases the effect of anticonvulsant, butethal.

Gefitinib: The CYP3A4 inducer, butethal, may decrease the serum concentration and therapeutic effects of gefitinib.

Griseofulvin: The barbiturate, butethal, decreases the effect of griseofulvin.

Hydrocortisone: The barbiturate, butethal, may decrease the effect of the corticosteroid, hydrocortisone.

Levonorgestrel: Phenobarbital decreases the effect of levonorgestrel

Medroxyprogesterone: The enzyme inducer, butethal, decreases the effect of the hormone agent, medroxyprogesterone.

Megestrol: The enzyme inducer, butethal, decreases the effect of the hormone agent, megestrol.

Methadone: The barbiturate, butethal, decreases the effect of methadone.

Metronidazole: The barbiturate, butethal, decreases the effect of metronidazole.

Nifedipine: The barbiturate, butethal, decreases the effect of the calcium channel blocker, nifedipine.

Norethindrone: This product may cause a slight decrease of contraceptive effect

Oxtriphylline: The barbiturate, butethal, decreases the effect of oxtriphylline.

Prednisolone: The barbiturate, butethal, may decrease the effect of the corticosteroid, prednisolone.

Prednisone: The barbiturate, butethal, may decrease the effect of the corticosteroid, prednisone.

Quinidine: The anticonvulsant, butethal, decreases the effect of quinidine.

Theophylline: The barbiturate, butethal, decreases the effect of theophylline.

Triamcinolone: The barbiturate, butethal, may decrease the effect of the corticosteroid, triamcinolone.