Brand name
- SERAX®
Drug Class
Benzodiazepines
Preparations
- Capsule 10, 20 and 30 mg
Indications
1. Alcohol withdrawal syndrome
2. Anxiety disorders (Social phobia, Post-traumatic stress disorder, Premenstrual syndrome, Insomnia Acute Panic Attack)
Pharmacology
- The exact mechanism of action of benzodiazepines has not yet been elucidated.
- Mechanism of action: May has effect on Gamma-Aminobutyric acid (GABA) >>> Increases the inhibitory effect of GABA (Increases the permeability of neuron membrane to Chloride ions) >>> Stabilization of neuronal membrane.
Metabolism
- Distribution: Peak plasma time >>> 2.8- 5.7 hours. Peak plasma concentration >>> 3 hours
- Metabolism: Glucoronic acid conjugation. No active metabolite. The cytochrome P450 system has not been shown to be involved in the disposition of oxazepam and, unlike many benzodiazepines, pharmacokinetic interactions involving the P450 system have not been observed with Oxazepam
- Absorption: 95-98% binds with plasma proteins
- Excretion: Urine
Dosing
1. Mild to moderate anxiety:
- 5-15 mg, 3 or 4 times daily
2. Severe anxiety agitation or anxiety associated with depression:
- 15-30 mg, 3 or 4 times daily
3. Elderly patients with anxiety, tension, irritability and agitation:
- Initial dose is 7.5 mg, 2-3 times daily.
- Increase cautiously to 15 mg, 3 or 4 times daily.
4. Alcoholics with tremulousness or anxiety on withdrawal:
- Dose is 15-30 mg, 3 or 4 times daily
- Oxazepam should not be administered to alcoholics with acute inebriation.
Drug Interactions
- Barbiturates
- Alcohol
- Sedatives
- Tricyclic antidepressants
- Non selective MAO inhibitors
- Phenothiazine and other antipsychotics
- Skeletal muscle relaxants
- Antihistamines
- Narcotic analgesics
- Anaesthetics
- Anticonvulsants
Adverse Effects
1. More common:
- Mild drowsiness
2. Less common:
- Transient Amnesia Or Memory Impairment
- Oedema
- Hypotension
- Skin Rashes (Morbilliform, Urticarial And Maculopapular)
- Nausea
- Hepatic Dysfunction, And Abdominal Pain
- Hypersensitivity
- Lethargy
- Altered Libido
- Slurred Speech
- Blurred Vision
- Disorientation
- Fever
- Leucopenia
- Tremor
- Paraesthesia
- Dizziness
- Vertigo
- Headache
- Syncope
- Ataxia,
- Confusion
- Hallucination
- Aggression
- Unpleasant dreams
- Paradoxical Reactions
Contraindications
1. Known hypersensitivity to benzodiazepines
2. Chronic obstructive airways disease with incipient respiratory failure
3. Sleep apnea
Pregnancy and Breastfeeding
Pregnancy: Category C
Lactation: Avoid using in nursing mother
Precautions
1. The pharmacokinetics of Oxazepam remain unaltered in older patients, however the elderly generally show increased central nervous system sensitivity to benzodiazepines, >>> may require a reduced dosage.
2. Pediatric: Not recommended in children less than 16 years of age.
3. Caution in patients with Hepatic diseases! >>> May require a reduced dosage.
4. Caution in patients with renal dysfunction! >>> May require a reduced dosage.
5. Caution in concomitant use with CNS-depressant medications! May cause synergistic effect >>> may increase sedation!
6. Avoid driving while taking Oxazepam!
7. Avoid using dangerous machinery vehicles while taking Oxazepam!
8. Impaired Respiratory Function: Caution in the use of Oxazepam is recommended in-patients with respiratory depression. In-patients with chronic obstructive pulmonary disease, benzodiazepines can cause increased arterial carbon dioxide tension and decreased arterial oxygen tension.
9. In general, benzodiazepines should be prescribed for short periods only (e.g. 2-4 weeks). Continuous long-term use of Oxazepam is not recommended.
10. Following the prolonged use of Oxazepam at therapeutic dose, withdrawal from the medication should be gradual >>> an individualised withdrawal timetable needs to be planned for each patient in whom dependence is known or suspected. (Periods from four weeks to four months) >>> abrupt withdrawal of benzodiazepines in-patients with convulsive disorders.
11. Abuse: Caution in administering Oxazepam to individuals known to be addiction prone or those whose history suggests they may increase the dosage on their own initiative.
12. Dependence: The use of benzodiazepines may lead to dependence as defined by the presence of a withdrawal syndrome on discontinuation of the drug.
13. Tolerance: As defined by a need to increase the dose in order to achieve the same therapeutic effect seldom occurs in-patients receiving recommended doses under medical supervision >>> Caution for Tolerance to sedation may occur with benzodiazepines especially in those with drug seeking behaviour.
14. Caution for hypotension after taking Oxazepam >>> especially in elderlies!
15. Caution in patients with Myasthenia Gravis >>> could increase the muscle weakness
16. Caution should be used in the treatment of patients with narrow-angle glaucoma >>> because of atropine-like side effects.
17. Oxazepam may cause Blood Dyscrasias >>> Do periodic Complete Blood Test.
18. Oxazepam is not recommended as primary therapy in-patients with depression and psychosis >>> psychiatric assessment and supervision are necessary if benzodiazepines are indicated. Benzodiazepines may increase depression in some patients, and may contribute to deterioration in severely disturbed schizophrenics with confusion and withdrawal. Caution for Suicidal tendencies may be present.
19. Paradoxical reactions such as acute rage, stimulation or excitement may occur; should such reactions occur, Oxazepam should be discontinued >>> Rebound phenomena.
20. Caution: Oxazepam may have Interference With Clinical, Laboratory And Other Tests:
- Oxazepam may decrease values of leukocytes in testing for leukopoiesis.
- Oxazepam may give high blood glucose level utilising the Somogyi procedure but not the glucose oxidase procedure.
21. Over-dosage:
- Clinical manifestations has wide ranges, from drowsiness to coma
22. Treatment:
- Activated charcoal should be given to reduce absorption.
- Do supportive treatments for any possible respiratory depression or hypotension
- Flumazenil (Benzodiazepine antagonist –Specific antidote) 0.2 mg IV in 13-30 minutes >>> If no response after 30 minutes, add 0.3 mg in 30 seconds one minute later. Maximum total dose: 3 mg/hr
Section
This document is prepared by the “Mental Health for All” team. This document is provided for information purposes only and does not necessarily represent endorsement by or an official position of the Essentials of Medicine. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient’s medical history.