Conversion of DDAVP 0.2mg to Micrograms
0.2mg of DDAVP (desmopressin) is equivalent to 200 micrograms (mcg).
Conversion Calculation
The conversion from milligrams (mg) to micrograms (mcg) follows a simple mathematical formula:
- 1 mg = 1000 mcg
- Therefore, 0.2 mg × 1000 = 200 mcg
Clinical Context of Desmopressin Dosing
Desmopressin (DDAVP) is a synthetic analogue of vasopressin with enhanced antidiuretic properties and reduced pressor activity compared to the natural hormone 1. The 200 mcg dose is commonly used in several clinical scenarios:
Common Dosing Applications
- Central Diabetes Insipidus: 200 mcg is within the therapeutic range for intranasal administration 2
- Nocturnal Enuresis: The oral tablet form at 200 mcg is a standard dose for children with monosymptomatic enuresis 3
- Hemostasis: For patients with mild hemophilia or von Willebrand disease 4
Formulation Considerations
Different formulations have different bioavailability:
- Intranasal administration has approximately 1/10th the potency of injectable desmopressin 1
- The oral lyophilizate 120 mcg is considered bioequivalent to the 200 mcg oral tablet in adults, though this equivalence may not directly apply to children 5
Safety Considerations
When administering 200 mcg (0.2 mg) of desmopressin, be aware of these important safety considerations:
- Hyponatremia Risk: Monitor serum sodium levels, especially in patients ≥65 years old or those on concomitant medications associated with hyponatremia 6
- Fluid Intake: Restrict fluid intake from 1 hour before until 8 hours after administration to reduce the risk of water intoxication and hyponatremia
- Renal Function: The half-life of desmopressin is significantly prolonged in patients with renal impairment (from 3 hours in healthy patients to 9 hours in severe renal impairment) 1
Special Populations
- Pediatric Patients: Dosing may need adjustment based on age and weight rather than using standard flat dosing 5
- Elderly: Higher risk of hyponatremia; ensure baseline sodium ≥135 mmol/L before initiating therapy 6
Remember that the correct dose conversion (0.2 mg = 200 mcg) is essential for accurate medication administration and patient safety.