PRECAUTIONS
General: Intranasal DDAVP at high dosage has infrequently produced a
slight elevation of blood pressure, which disappeared with a reduction in dosage.
The drug should be used with caution in patients with coronary artery insufficiency
and/or hypertensive cardiovascular disease because of possible rise in blood
pressure.
DDAVP should be used with caution in patients with conditions associated with fluid and electrolyte imbalance, such as cystic fibrosis, heart failure and renal disorders because these patients are prone to hyponatremia.
Ensure that in children administration is under adult supervision in order
to control the dose intake.
Rare severe allergic reactions have been reported with DDAVP. Anaphylaxis has been reported rarely with intravenous and intranasal administration of DDAVP.
Central Cranial Diabetes Insipidus: Since DDAVP Rhinal Tube (desmopressin acetate rhinal tube) is
used intranasally, changes in the nasal mucosa such as scarring, edema, or other
disease may cause erratic, unreliable absorption in which case intranasal DDAVP
should not be used. For such situations, DDAVP Injection should be considered.
Laboratory Tests: Laboratory tests for following the patient with central
cranial diabetes insipidus or post-surgical or head trauma-related polyuria
and polydipsia include urine volume and osmolality. In some cases plasma osmolality
measurements may be required.
Carcinogenesis, Mutagenesis, Impairment of Fertility: Studies with DDAVP
have not been performed to evaluate carcinogenic potential, mutagenic potential
or effects on fertility.
Pregnancy Category B: Fertility studies have not been done. Teratology
studies in rats and rabbits at doses from 0.05 to 10 mcg/kg/day (approximately
0.1 times the maximum systemic human exposure in rats and up to 38 times the
maximum systemic human exposure in rabbits based on surface area, mg/m2)
revealed no harm to the fetus due to DDAVP. There are, however, no adequate
and well controlled studies in pregnant women. Because animal reproduction studies
are not always predictive of human response, this drug should be used during
pregnancy only if clearly needed.
Several publications of desmopressin acetate's use in the management of diabetes
insipidus during pregnancy are available; these include a few anecdotal reports
of congenital anomalies and low birth weight babies. However, no causal connection
between these events and desmopressin acetate has been established. A fifteen
year, Swedish epidemiologic study of the use of desmopressin acetate in pregnant
women with diabetes insipidus found the rate of birth defects to be no greater
than that in the general population; however the statistical power of this study
is low. As opposed to preparations containing natural hormones, desmopressin
acetate in antidiuretic doses has no uterotonic action and the physician will
have to weigh the therapeutic advantages against the possible risks in each
case.
Nursing Mothers: There have been no controlled studies in nursing mothers.
A single study in postpartum women demonstrated a marked change in plasma, but
little if any change in assayable DDAVP (desmopressin acetate) in breast milk
following an intranasal dose of 10 mcg. It is not known whether this drug is
excreted in human milk. Because many drugs are excreted in human milk, caution
should be exercised when DDAVP is administered to a nursing woman.
Pediatric Use: Central Cranial Diabetes Insipidus: DDAVP Rhinal
Tube has been used in pediatric patients with diabetes insipidus. Use in
infants and pediatric patients will require careful fluid intake restriction
to prevent possible hyponatremia and water intoxication. Fluid restriction should
be discussed with the patient and/or guardian. (See WARNINGS.) The dose
must be individually adjusted to the patient with attention in the very young
to the danger of an extreme decrease in plasma osmolality with resulting convulsions.
Dose should start at 0.05 mL or less.
There are reports of an occasional change in response with time, usually greater than 6 months. Some patients may show a decreased responsiveness, others a shortened duration of effect. There is no evidence this effect is due to the development of binding antibodies but may be due to a local inactivation of the peptide.
Geriatric Use: Clinical studies of DDAVP Rhinal Tube (desmopressin acetate rhinal tube) did not include
sufficient numbers of subjects aged 65 and over to determine whether they respond
differently from younger subjects. Other reported clinical experience has not
identified differences in responses between elderly and younger patients. In
general, dose selection for an elderly patient should be cautious, usually starting
at the low end of the dosing range, reflecting the greater frequency of decreased
hepatic, renal, or cardiac function, and of concomitant disease or other drug
therapy.
This drug is known to be substantially excreted by the kidney, and the risk
of toxic reactions to this drug may be greater in patients with impaired renal
function. Because elderly patients are more likely to have decreased renal function,
care should be taken in dose selection, and it may be useful to monitor renal
function. DDAVP is contraindicated in patients with moderate to severe renal
impairment (defined as a creatinine clearance below 50ml/min). (See CLINICAL
PHARMACOLOGY, Human Pharmacokinetics and CONTRAINDICATIONS
)
Use of DDAVP Rhinal Tube (desmopressin acetate rhinal tube) in geriatric patients will require careful fluid intake
restrictions to prevent possible hyponatremia and water intoxication. Fluid
restriction should be discussed with the patient. (See WARNINGS.)