Alprazolam
Drug class: Benzodiazepines, BDZs
Alprazolam(中文:阿普唑侖) is a short-acting benzodiazepine. It is used in the short-term treatment of anxiety disorders, specifically panic disorder or generalized anxiety disorder (GAD). GAD improvement occurs generally within a week. Alprazolam is generally taken by mouth.
Pronunciation[edit]
Alprazolam 0.25mg (XANAX)[edit]
Drug Names[edit]
| Generic Name 藥名 | HA Code 藥物代碼 | Classification藥物分類 |
|---|---|---|
| Alprazolam Tablet 0.25 mg | ALPR01 | DDA |
| Alprazolam Tablet 0.5 mg | ALPR02 | DDA |
Mechanism of Action[edit]
- Alprazolam is a benzodiazepine.
- Gama-Aminobutyric acid (GABA) is an inhibitory neurotransmitter, acting on the GABA receptors in the central nervous system (CNS), thus inhibiting the nerve impulses.
- Alprazolam acts on the benzodiazepine receptors in the brain and the spinal cord. Benzodiazepine receptors in the CNS are linked with GABA receptors as a complex.
- Alprazolam by binding to the benzodiazepine receptors results in activation of the GABA-benzodiazepine receptor complex, resulting in inhibition of nerve impulses, overall depression of brain and spinal cord.
- Thus alprazolam use helps to promote muscle relaxation, reduce anxiety, control of convulsions and promote sleep.
Dosage[edit]
| Short-term use in anxiety | By mouth
|
|---|
Side Effects[edit]
Sedative drugs, including alprazolam, have been associated with an increased risk of death.
Possible side effects include:
| Very common (>10% of incidence)
or Common (1-10% of incidence) |
|
|---|---|
| Infrequent (0.1 -1% of incidence) |
|
| Rare (<0.1% of incidence) |
|
Overdosage can produce CNS depression and coma.
Paradoxical reactions
Although unusual, the following paradoxical reactions have been shown to occur:
- aggression
- mania, agitation, and restlessness
- rage
- twitches and tremor
Pharmacokinetics[edit]
| Oral bioavailability | Pregabalin is well absorbed after oral doses. |
|---|---|
| Onset of action | Peak plasma concentrations occur within 1 to 2 hours of a dose. |
| Metabolism | Alprazolam is metabolized in the liver, mainly by the cytochrome P450 isoenzyme CYP3A4. |
| Elimination half-life | Alprazolam is eliminated in the urine.
The mean elimination half-life is 11 to 15 hours. |
Drug Management[edit]
Monitoring[edit]
- changes in mood, the development or worsening depression, and/or any thoughts or behaviour of suicide.
- Fall prevention in elderly patients
Dependence and Withdrawal[edit]
Dependence is particularly likely in patients with a history of alcohol or drug abuse and in those with marked personality disorders. Alprazolam should therefore be withdrawn by gradual reduction of the dose after regular use for even a few weeks; the time needed for withdrawal cab vary from about 4 weeks to a year or more.
Drug interaction[edit]
Enhanced sedation or respiratory and cardiovascular depression may occur if alprazolam is given with other drugs that have CNS-depressant properties; these include alcohol, antidepressants, sedative antihistamines, antipsychotics, and opioid analgesics. Alprazolam is primarily metabolized via CYP3A4. Combining CYP3A4 inhibitors such as cimetidine, erythromycin, and itraconazole delay the hepatic clearance of alprazolam, which may result in its accumulation and increased severity of its side-effects.
| Drugs given with alprazolam | Potential Effect |
|---|---|
| Alcohol | Alcohol and alprazolam taken in combination have a synergistic effect on one another, which can cause severe sedation and intoxication. |
| Opioid analgesics
Codeine, morphine, oxycodone |
Increased sedative effect |
| Antidepressants | Plasma concentration of alprazolam increased by FLUOXETINE. |
| Antifungals | Plasma concentration of alprazolam increased by KETOCONAZOLE, ITRACONAZOLE – avoid concomitant use |
| Antihistamines (e.g. promethazine) | Increased sedative effect |
| Antipsychotics | Alprazolam possibly increases plasma concentration of haloperidol |
| Digoxin | Alprazolam increases plasma concentration of DIGOXIN (increased risk of toxicity) |
Caution[edit]
- particular care in pregnancy,
- elderly, due to increased susceptibility to side-effects, especially loss of coordination and drowsiness
- people with history of alcohol dependence or abuse
- people with history of drug dependence or abuse
- people with psychiatric disorders
- avoid prolonged use and abrupt withdrawal thereafter
Contra-indications[edit]
- Should be avoided in severe hepatic impairment
- Chronic psychosis
- Respiratory depression
- Myasthenia gravis
- Acute narrow-angle glaucoma
Hepatic impairment[edit]
- Start with smaller initial doses or reduce dose.
- Can precipitate coma.
Renal impairment[edit]
- Start with small doses in severe impairment.
Pregnancy[edit]
The use of alprazolam during pregnancy is associated with congenital abnormalities.
Breast-feeding[edit]
Use during breast feeding is not recommended.
Driving and skilled tasks[edit]
May impair judgment and increase reaction time, and so affect ability to drive or operate machinery.
FAQ[edit]
How should I take the tablet?[edit]
If you get nauseous after taking alprazolam on an empty stomach, try taking it with food.
What should I avoid while taking?[edit]
Do not eat grapefruit or drink grapefruit juice.
Do not drink any alcohol or use recreational drugs while taking alprazolam
What happen if I overdose?[edit]
Contact your primary care doctor. If emergency situation, call 999
What happen if I miss a dose?[edit]
Take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
