Barbiturate Abuse and Dependence

What barbiturates are

Barbiturates were the main sleeping pills and sedatives from the early 1900s until the 1960s. They enhance the effect of GABA, the brain's main calming chemical, and at higher doses open nerve channels directly. That second action is why they are much more dangerous in overdose than newer benzodiazepines.

Today they are prescribed far less, but are still used for:

• Phenobarbital: epilepsy, seizures in newborns, and hospital alcohol withdrawal
• Butalbital: in combination tablets with acetaminophen or aspirin and caffeine, for tension headaches
• Pentobarbital: in hospitals and veterinary medicine
• Methohexital: short anesthesia

Misused barbiturates usually come from diverted prescriptions, often butalbital headache pills, or from illegal sources. They are called "barbs", "reds", "yellow jackets" or "downers".

Effects of barbiturate use

Effects resemble alcohol intoxication. Combining barbiturates with alcohol, opioids, benzodiazepines or sleeping pills multiplies the risk of fatal breathing suppression.

Signs of barbiturate abuse

• taking more than prescribed or using someone else's tablets
• running out of prescriptions early or seeing several doctors
• appearing drunk without the smell of alcohol
• sluggishness, slurred speech, staggering, memory gaps
• irritability, hostility or mood swings
• needing more for the same effect (tolerance)
• feeling anxious, shaky or unable to sleep without them
• daily headaches that worsen when butalbital wears off (medication-overuse headache)

Overdose

Barbiturates have a narrow therapeutic index: the gap between an effective and a toxic dose is small. Tolerance to the sedative "high" develops faster than tolerance to the effect on breathing, so people chasing the same high can take a lethal amount.

Signs of overdose:

• deep drowsiness or unresponsiveness
• slow, shallow or irregular breathing
• small or fixed pupils, low body temperature
• weak pulse and low blood pressure
• blisters on the skin over pressure points (a classic but uncommon sign)

There is no antidote for barbiturates. Hospital care includes airway and breathing support, often with a ventilator, activated charcoal in some cases, fluids and medicines to support blood pressure, and sometimes urine alkalinization or dialysis to remove phenobarbital. Naloxone does not reverse barbiturates but should still be given if opioids may be involved.

Withdrawal

After regular use, stopping suddenly can be life-threatening. Withdrawal is similar to severe alcohol withdrawal and usually begins within 1 to 3 days, depending on which barbiturate was used:

• anxiety, restlessness, insomnia, tremor
• sweating, nausea, vomiting, rapid heartbeat and low blood pressure on standing
• muscle twitching and weakness
• seizures, often 2 to 3 days after stopping short-acting barbiturates
• delirium, with confusion, hallucinations and high fever, which can be fatal

Supervised withdrawal

Doctors calculate how much barbiturate a person is dependent on and replace it with a long-acting barbiturate, usually phenobarbital, then reduce the dose slowly, often by about 10% a day or more gradually for long-term users. This is done in hospital or a specialist detox unit for heavy users.

Diagnosis

A doctor diagnoses sedative, hypnotic or anxiolytic use disorder using the same DSM-5-TR criteria as other substance use disorders: loss of control, cravings, harm to life roles, risky use, tolerance and withdrawal. Urine drug screens detect barbiturates; phenobarbital can be detected for weeks. Assessment also screens for alcohol and opioid use, depression, anxiety and suicide risk, because these commonly co-occur.

Treatment and recovery

• Medically supervised withdrawal as above
• Cognitive behavioral therapy to manage triggers, anxiety and sleep problems without sedatives
• Treatment of the original problem: insomnia (cognitive behavioral therapy for insomnia), anxiety (therapy and non-addictive medicines) or headaches (preventive treatment instead of butalbital)
• Treatment of other substance use, including medications for alcohol or opioid use disorder
• Peer support groups and family involvement

For general information about substance use disorders, see drug abuse and signs of drug abuse. Benzodiazepines cause a similar but usually less dangerous dependence; see benzodiazepine dependence.

Complications

• fatal overdose, especially combined with alcohol or opioids
• withdrawal seizures and delirium
• accidents and falls from impaired coordination
• memory problems
• depression and suicide risk
• in pregnancy, birth defects and withdrawal in the newborn

Frequently asked questions

Why are barbiturates so dangerous?

Their effective dose and fatal dose are close together, and tolerance to the sedative effect builds faster than tolerance to the effect on breathing. Combining them with alcohol or opioids sharply increases the risk of breathing stopping. There is no antidote.

Is barbiturate withdrawal dangerous?

Yes. Stopping suddenly after regular use can cause seizures, delirium, high fever and death, similar to severe alcohol withdrawal. Withdrawal should always be managed by a doctor, usually with a slow taper using phenobarbital.

Is butalbital a barbiturate?

Yes. Butalbital is a barbiturate found in combination tablets for tension headaches. Frequent use can cause dependence, withdrawal seizures and medication-overuse headaches. Many headache specialists now avoid prescribing it.

How long do barbiturates stay in your system?

It depends on the drug. Short-acting barbiturates may be detected in urine for 1 to 4 days. Long-acting phenobarbital can be detected for several weeks, because the body removes it slowly.