ddavp

Action

Enhances water reabsorption by increasing permeability of renal collecting ducts to adenosine monophosphate and water, thereby reducing urinary output and increasing urine osmolality. Also increases factor VIII (antihemophilic factor) activity.

Availability

Injection: 4 mcg/ml in single-dose 1-ml ampules and multidose 10-ml vials

Intranasal solution: 0.1 mg/ml, 1.5 mg/ml

Intranasal spray (DDAVP): 0.1 mg/ml (10 mcg/spray) in 5-ml spray pump bottle

Tablets: 0.1 mg, 0.2 mg

Indications and dosages

➣ Diabetes insipidus

Adults and children older than age 12: 0.05 mg P.O. b.i.d.; adjust dosage based on patient response. Or 0.1 to 0.4 ml (10 to 40 mcg) daily intranasally as a single dose or in two or three divided doses. Or 0.5 ml (2 mcg) to 1 ml (4 mcg) daily I.V. or subcutaneously, usually in two divided doses.

Children ages 3 months to 12 years: 0.05 to 0.3 ml/day intranasally in one or two divided doses

➣ Hemophilia A; von Willebrand's disease type I

Adults and children: 0.3 mcg/kg I.V.; may repeat dose if needed. Or 300 mcg of intranasal solution containing 1.5 mcg/ml; for patients weighing less than 50 kg (110 lb), total dosage of 150 mcg (one spray of solution containing 1.5 mg/ml into a single nostril) is usually sufficient. If needed to maintain hemostasis during surgery, give intranasal dose 2 hours before surgery or give I.V. dose 30 minutes before surgery.

Off-label uses

• Chronic autonomic failure (such as nocturnal polyuria, overnight weight loss, morning orthostatic hypotension)

Contraindications

• Hypersensitivity to drug

• Moderate to severe renal impairment

• Hemophilia A with factor VIII levels less than or equal to 5%

• Von Willebrand's disease type IIB

• Impaired level of consciousness (intranasal form)

Precautions

Use cautiously in:

• coronary artery disease, hypertensive cardiovascular disease, fluid and electrolyte imbalances

• breastfeeding patients.

Administration

• Adjust morning and evening dosages as appropriate to minimize frequent urination and risk of water intoxication.

• Give I.V. dose (diluted in normal saline solution) by infusion over 15 to 30 minutes.

• Monitor pulse and blood pressure throughout I.V. infusion

☞ When giving to child with diabetes insipidus, carefully restrict fluid intake to prevent hyponatremia and water intoxication.

Adverse reactions

CNS: headache, dizziness, insomnia

CV: slight blood pressure increase, chest pain, palpitations

EENT: rhinitis, epistaxis, sore throat

GI: nausea, abdominal pain

GU: vulvar pain

Respiratory: cough

Other: local erythema, flushing, swelling or burning after injection

Interactions

Drug-drug. Carbamazepine, chlorpropamide, pressor drugs: potentiation of desmopressin effects

Patient monitoring

• Monitor urine volume and specific gravity, plasma and urine osmolality, and electrolyte levels in patients with diabetes insipidus.

• Monitor factor VIII antigen levels, activated partial thromboplastin time, and bleeding time in patients with hemophilia.

☞ When giving to child with diabetes insipidus, carefully monitor fluid intake and output.

Patient teaching

• Instruct patient to take drug exactly as prescribed and not to interchange strengths or delivery systems.

• Teach patient how to use prescribed delivery system if taking drug by other than oral route.

• Instruct patient with diabetes insipidus to avoid overhydration and to weigh himself daily. Tell him to report weight gain or swelling of arms or legs.

• If patient is using nasal spray, teach him to inspect nasal membranes regularly and to report increased nasal congestion or swelling.

• Caution elderly patient not to increase fluid intake beyond that sufficient to satisfy thirst.

• Instruct patient to report headache, respiratory difficulty, nausea, or abdominal pain to prescriber.

• As appropriate, review all significant adverse reactions and interactions, especially those related to the drugs mentioned above.