oxazepam

Action

Suppresses CNS stimulation at limbic and subcortical levels by potentiating effects of gamma-aminobutyrate, an inhibitory neurotransmitter. This suppression reduces anxiety and diminishes alcohol withdrawal symptoms.

Availability

Capsules: 10 mg, 15 mg, 30 mg

Tablets: 15 mg

Indications and dosages

➣ Mild to moderate anxiety

Adults: 10 to 15 mg P.O. three to four times daily

➣ Severe anxiety; alcohol withdrawal symptoms

Adults: 15 to 30 mg P.O. three to four times daily

Dosage adjustment

• Elderly patients

Off-label uses

• Insomnia

Contraindications

• Hypersensitivity to drug or tartrazine (some products)

Precautions

Use cautiously in:

• hepatic dysfunction, severe chronic obstructive pulmonary disease, myasthenia gravis, CNS depression, uncontrolled severe pain

• history of suicide attempt or drug abuse

• concurrent use of other benzodiazepines

• elderly or debilitated patients

• pregnant or breastfeeding patients.

Administration

• Administer with or without food.

• Taper dosage after long-term therapy.

Adverse reactions

CNS: dizziness, drowsiness, headache, confusion, poor memory, hangover effect, slurred speech, depression, paradoxical stimulation

CV: orthostatic hypotension, hypotension, ECG changes, tachycardia

EENT: blurred vision, mydriasis, tinnitus

GI: nausea, vomiting, constipation, diarrhea

GU: urinary retention, urinary incontinence

Hematologic: leukopenia

Hepatic: jaundice, hepatitis

Respiratory: respiratory depression

Skin: rash, dermatitis, itching

Other: physical and psychological drug dependence, drug tolerance, withdrawal symptoms

Interactions

Drug-drug. Azole antifungals: increased oxazepam blood level, greater risk of toxicity

Hormonal contraceptives, phenytoin: decreased oxazepam efficacy

Levodopa: decreased levodopa efficacy

Other CNS depressants (including anti-depressants, antihistamines, other benzodiazepines, sedative-hypnotics, opioids): additive CNS depression

Theophylline: decreased sedative effect of oxazepam

Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase: increased levels

Hematocrit, thyroid uptake of sodium iodide ¹²³I and¹³¹I, white blood cells: decreased values

Drug-food. Cabbage: decreased drug blood level

Drug-herbs. Chamomile, hops, kava, valerian, skullcap: increased CNS depression

Drug-behaviors. Alcohol use: increased CNS depression

Patient monitoring

☞ Monitor liver function tests and watch for signs and symptoms of hepatitis.

• Check vital signs. Stay alert for respiratory depression, orthostatic hypotension, and tachycardia.

• Monitor neurologic status. As needed, take measures to prevent injury.

• Watch for signs and symptoms of psychological or physical dependence.

• When tapering, watch for withdrawal symptoms.

Patient teaching

• Tell patient he may take with or without meals, but should avoid cabbage.

• Advise patient to take exactly as prescribed. Tell him drug can cause dependence, and emphasize importance of following tapering instructions to avoid withdrawal symptoms.

☞ Urge patient to immediately report unusual tiredness, nausea, appetite loss, or yellowing of skin or eyes.

• Tell patient to change position slowly to avoid blood pressure decrease.

• Instruct patient to report severe dizziness, weakness, persistent drowsiness, palpitations, or visual changes.

• Advise patient not to drink alcohol.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects vision, cognition, and balance.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, herbs, and behaviors mentioned above.