Definition
Despite being known as diabetes, the "insipid" form has nothing to do with diabetes mellitus, a disease related to a deficiency in insulin action; diabetes insipidus on the other hand expresses a rather rare metabolic deficit, characterized by intense thirst and excessive emission of urine.
Causes
Diabetes insipidus is the consequence of a metabolic alteration which consists in the reduction of the synthesis of vasopressin (antidiuretic hormone secreted by the pituitary gland), associated with a marked decrease in renal sensitivity to its action. The causes of origin can be varied: infections, neurological surgery, chronic renal failure, hypercalcemia / hyperkalaemia, hypothalamic malformations, head trauma, intracranial tumor.
Symptoms
The symptoms that characterize diabetes insipidus are concretized in thirst - permanent and insatiable - and in the excessive excretion of urine, which can sometimes reach 18 liters a day; it follows the tendency to dehydration, associated with weight loss and, in the most serious cases, death. The urine also has low specific weight and osmolarity.
Information on Diabetes Insipidus - Drugs for the Treatment of Diabetes Insipidus is not intended to replace the direct relationship between health professional and patient. Always consult your doctor and / or specialist before taking Diabetes Insipidus - Drugs for Diabetes Insipidus Treatment.
drugs
The main objective of treatment for diabetes insipidus is undoubtedly to decrease the amount of urine excreted, in addition to replacing the fluids lost through urination. Since diabetes insipidus is closely related to a functional alteration of vasopressin, the pharmacological treatment consists of hormone replacement therapy. In other cases, diabetes insipidus may depend on a lack of vasopressin activity in the kidney (nephrological diabetes insipidus), although vasopressin production is preserved: in similar situations, the disease cannot be corrected with the exogenous administration of ADH, and the patient must take large amounts of water, take diuretics and limit the sodium intake with the diet.
→ Diuretics, in fact, are able to sensitize the renal tubules to the action of vasopressin
→ a low-sodium diet can help reduce the amount of water lost through urine
When diabetes insipidus is linked to a brain tumor, surgical removal of the neoplastic mass can cancel the metabolic alteration.
Antidiuretic hormone : the first line therapy for pituitary diabetes insipidus is represented by the administration of the antidiuretic hormone and its analogues; the dosage must be carefully established by the doctor after accurate diagnosis of the patient, in order to produce a slight diuresis during the day, thus avoiding water intoxication.
- Vasopressin (eg Pitressin): the drug, also used for the treatment of esophageal varices, is not on the market in Italy due to its side effects (anaphylaxis, abdominal cramps, hypertension, peripheral ischemia, headache, nausea, pallor, tenesmus, fluid retention and, in the most serious cases, gangrene). However, it is injected intramuscularly or subcutaneously (5-20 units every 4 hours).
- Desmopressin (eg Minirin / Ddvap): it is an analogue of vasopressin, able to carry out the same therapeutic activities but with a longer duration of action and with fewer side effects; more precisely, desmopressin has no vasoconstrictor effects, therefore it does not cause hypertension. The drug is available in the form of sublingual tablets (60-120 mcg), tablets to be taken with water (0.1-0.2 mg), solution for injection (4 mcg, indicated for patients without consciousness and for injection after surgery), oral drops (250 mcg) and nasal spray of 0.125 mcg. For the precise dosage consult your doctor; in general, the indicative dose is 300 mcg for starting oral therapy, and 300-600 mcg for oral maintenance therapy. When taking desmopressin, it is recommended to take liquids only if really necessary.
Thiazide diuretics : these drugs exert a particular paradoxical beneficial effect in the treatment of neurogenic and partial pituitary diabetes insipidus. Drugs are useful for reducing the amount of urine excreted:
- Chlorthalidone (eg Igroton): it is recommended to start therapy with a dose of 100 mg, to be taken twice a day. The maintenance dose is 50 mg per day.
- Hydrochlorothiazide (eg Esidrex, Ifirmacombi, CoAprovel): start therapy with 50 mg of active, taken orally once a day. The maintenance dose is expected to take 100 mg of active per day. Consult your doctor before taking this medicine.
Potassium-sparing diuretics : drugs are also indicated for the treatment of diabetes insipidus, since they help the kidneys to use vasopressin in a better way, decreasing the amount of excreted urine and ensuring the body a constant level of potassium.
Sulfonylureas : sometimes some sulfonylureas can be used in the treatment of diabetes insipidus (partial pituitary type), even if they are not the first choice treatment. Probably, these drugs are able to sensitize the renal tubules to the hormonal activity of the remaining vasopressin. Blood glucose should be constantly monitored in patients who use it, since the drug can cause hypoglycemia.
- Chlorpropamide (eg Diabemide, Clorprop FN): indicatively, the dosage of the drug is 350 mg per day for adults and 200 mg per day for children with diabetes insipidus.
Antiepileptics : just like the previous drug, some antiepileptics are also used in therapy to lighten the typical symptoms of diabetes insipidus; although not the first-line drug for the treatment of this disease, carbamazepine appears to act by increasing the sensitivity of the renal tubules to the action of vasopressin.
- Carbamazepine (eg. Tegretol, Carbamazepine EG): at the dose of 200 mg, to be taken 1-2 times a day, carbamazepine can be used for the treatment of partial pituitary diabetes insipidus.
