Barbiturates were first prescribed for medical use in the early 1900s. Since then, more than 2,500 barbiturates have been synthesized, and at the peak of their popularity, about 50 were marketed for human use. Today, only about a dozen are still in medical use. Barbiturates induce a broad spectrum of central nervous system depression, from mild sedation to coma, and have been used as sedatives, hypnotics, anesthetics, and anticonvulsants. The primary difference among these drugs is how quickly they produce the desired effect, and the duration of those effects. Barbiturates are classified as ultrashort, short, intermediate, and long-acting.
The ultrashort-acting barbiturates induce anesthesia within about one minute after intravenous administration. Those in current medical use are the Schedule IV drug methohexital (Brevital®), and the Schedule III drugs thiamyl (Surital®) and thiopental (Pentothal®). Barbiturate abusers typically prefer the Schedule II short-acting and intermediate-acting barbiturates that include amobarbital (Amyta®), pentobarbital (Nembutal®), secobarbital (Seconal®), and Tuinal (an amobarbital/secobarbital combination product). Other short and intermediate-acting barbiturates are in Schedule III and include butalbital (Fiorina®), butabarbital (Butisol®), talbutal (Lotusate®), and aprobarbital (Alurate®). After oral administration, the onset of action is from 15 to 40 minutes, and the effects last up to six hours. These drugs are primarily used for insomnia and preoperative sedation. Veterinarians use pentobarbital for anesthesia and euthanasia.
Long-acting barbiturates include phenobarbital (Luminal®) and mephobarbital (Mebaral®), both of which are in Schedule IV. These drugs take effect in about one hour and last for about 12 hours, and are typically used for daytime sedation and for the treatment of seizure disorders.
While barbiturate abuse may not be as common as some other drugs today, statistics show that it is still a significant health risk. About 9% of Americans will abuse a barbiturate at some time during their life. The increase in barbiturate abuse may be caused by the popularity of stimulating drugs (“uppers”) like cocaine and methamphetamines. The barbiturates (“downers”) counteract the excitement and alertness obtained from the stimulating drugs.
Unfortunately, many of today’s drug abusers may be too young to know about the death and dangerous effects barbiturates caused in the 1970s, so they aren’t aware of the risks of using them.