There are no side effects of dDAVP except water intoxication. If you are experiencing unusual psychological changes on treatment, you should have your plasma sodium checked to see if it is low, a sign of water intoxication.

There is no known association between CDI and night terrors. However, I suppose the latter could be caused by dehydration resulting from inadequate control of the CDI or fever.

Anorexia nervosa can be associated with DI and deficient secretion of the antidiuretic hormone, vasopressin in someone who has CDI. These deficiencies are slowly reversible if the patient regains and keeps her normal weight for six months or more. NDI has not been demonstrated in anorexia nervosa, but it could also occur because some of the patients with DI do not have a vasopressin deficiency but do have hypokalemia (low potassium), which can interfere with the antidiuretic action of the hormone. It is also possible, if not likely, that some patients with anorexia nervosa have a form of dipsogenic DI due to a reversible abnormality in the thirst mechanism. Therefore, treatment with dDAVP or thiazide diuretics should be given very cautiously since they may produce water intoxication.

DI is not known to cause mood swings. If they are severe, mood swings sometimes are associated with episodes of excess drinking that cause transient DI, but this is unusual. Severe emotional disturbances (e.g., schizophrenia) are sometimes associated with long periods (weeks, months, or even years) of excessive drinking and urination that is called psychogenic polydipsia, but this is generally not associated with mood swings. If a patient has mood swings with chronic or sustained DI, the problems are probably unrelated and simply occurred together by coincidence.

As far as we know, CDI does not cause any type of mental disorder or disturbance. However, if it develops in infancy and results in prolonged episodes of sever unrecognized dehydration, the latter could result in permanent brain damage and mental retardation.

Eventually, there may be a genetic cure for NDI since it should be one of the genetic disorders for which it is easiest to deliver the normal gene to the correct tissue. Even so, this type of treatment is likely to be years away since there are ethical and technical issues that have to be resolved first.

The gene involved in familial DI depends on which type of DI it is. In CDI, the mutation is usually in the gene that directs the production of vasopressin and two associated proteins. This gene is on chromosome 20. However there is another type of familial CDI that is due to a recessive mutation in an as yet unidentified gene located on the x-chromosome. This type of CDI affects only males, but can be carried by females. In NDI, the mutation is either a gene on the x-chromosome that encodes the vasopressin receptor on in a different gene on an autosome that encodes a protein known as aquaporin that forms water channels in the kidney. In familial dipsogenic DI, we do not have any information yet as to which gene or genes are responsible.

The gene involved in familial DI depends on which type of DI it is. In CDI, the mutation is usually in the gene that directs the production of vasopressin and two associated proteins. This gene is on chromosome 20. However, there is another type of familial CDI that is due to a recessive mutation in an as yet unidentified gene located on the x-chromosome. This type of CDI affects only males but can be carried by females. In NDI, the mutation is either a gene on the x-chromosome that encodes the vasopressin receptor or in a different gene on an autosome that encodes a protein known as aquaporin that forms water channels in the kidney. In familial dipsogenic DI we do not have any information yet as to which gene or genes are responsible.

CDI can result from at least two kinds of genetic mutations. The most common one affects both males and females and can be transmitted from father to son, or father to daughter. On average, about half the children will be affected. The other type of familial CDI is due to a mutation on the x-chromosome. It affects only males and cannot be passed from father to son. It can be passed to a daughter but she will not get DI because the effect of the mutation is prevented by the good gene on her other x-chromosome (males have only one). However, she can pass it to her son who will get CDI. The genetic forms of CDI usually begin in the first 10 years of life. If the CDI did not start until later, it is probably not genetic unless the patient has other affected relatives.

It sounds as though you have the autosomal dominant form of familial pituitary DI (adFPDI). If so, your affected children have a 50-50 chance of passing the disease to each of their children. If the genetic mutation responsible for the adFPDI in your family has not already been determined, you should have genetic analysis performed because the information will enable your children to have their children tested at birth (or even before) to find out if they will also get CDI.

DDAVP is probably not causing breast. However, it might be due to elevations in serum prolactin, which happens in some patients with CDI. If your doctor has not already done so, he may want to order a test of serum prolactin.

Gestational DI is a type of DI that develops during pregnancy and usually stops or at least gets better several weeks after delivery. It is usually due to a deficiency of the antidiuretic hormone, vasopressin, and is due to increased destruction of the hormone by an enzyme made by the placenta. In some if not all patients, there may also be underlying damage to the posterior pituitary that prevents a compensatory increase in hormone secretion that would otherwise occur during pregnancy. This type of DI can be easily and safely treated with dDAVP, since it is more resistant to degradation by the enzyme that destroys vasopressin itself. Recently, we have discovered that there is another type of gestational DI that is due solely to an abnormality in the thirst mechanism. This type of gestational DI cannot be treated safely with dDAVP because it results in excessive water retention and a condition known as water intoxication. Distinguishing between the two types of gestational DI is not easy and is best left to a specialist in that area.

CDI itself does not interfere with menstruation or fertility. However, it may be associated with these or other problems if the disease or injury that caused the DI also damages adjacent parts of the brain or pituitary where other hormones are normally produced. Head trauma is one of the things that can cause this kind of collateral damage, but it does not always do so. Therefore, each patient with CDI must be evaluated separately to determine if any of the other hormones have been affected. Some of the other hormones (cortical, thyroid, prolactin, growth hormone, and in males, testosterone) can be evaluated reliably only by laboratory tests. However, if a woman has normal menstrual periods, the hormones that regulate or come from the ovaries (LH (luteinizing hormone), FSH (follicle stimulating hormone), estradiol, and progesterone) are probably normal and do not need to be tested. If there is any doubt about the normality of her menstrual periods, these hormones can be tested by a qualified endocrinologist or gynecologist. Neither CDI nor dDAVP treatment have any known adverse effect on pregnancy or the fetus. The incidence of miscarriage or fetal malformations appears to be no greater than in women without CDI. A mother with CDI will not pass the disease to her children unless she (or the father) have one of the familial (genetic) forms. Depending on the extent of pituitary damage, some women may have difficulties with labor or nursing, but these problems usually can be managed quite easily by the obstetrician.

CDI itself does not cause infertility but some of the diseases that cause CDI occasionally do so. If you truly have CDI (and not dipsogenic DI) it is perfectly safe to take dDAVP before and during pregnancy. It does not affect fertility or the unborn fetus, provided you remember to drink only when you are thirsty. Your serum sodium level will normally be lower (by 5 mEq/l) during pregnancy.

DI does not cause loss of menstrual periods or weight gain. However, some of the diseases that cause DI can also cause these other two problems. It is reassuring that your CT scan was normal but you should also have an MRI to look for possible causes of your DI and other problems. You should also have tests of your thyroid and ovarian function since they could be responsible for your weight gain and loss of menstruation.

Neither CDI or dDAVP treatment is risky for the fetus. As far as we know, dDAVP is completely safe during pregnancy. It has not been associated with any significant increase in spontaneous abortions or fetal malformations. The only risk is water intoxication, but that is no greater than in any other DI patient and can be avoided by remembering to drink only when you are truly thirsty. You and your doctor should also remember that serum sodium is normally lower during pregnancy so the laboratory criteria for water intoxication are different than in the nonpregnant state.

DDAVP may get into breast milk but, if it does, it should have no significant effect on a nursing baby.

There is no reason to stop desmopressin therapy for CDI during pregnancy. In fact, it is sometimes necessary to increase the dose slightly. There is no particular advantage to taking the tablets rather than the nasal spray. Finally, it is also unnecessary to stop dDAVP during nursing because the amount that the baby absorbs with breast milk is too small to have any significant effect.

If your CDI and hypothyroidism are fully treated, they should not interfere with your fertility. They also should not affect your life expectancy nor have any effect on other medications that you may be taking. However, the disease that apparently caused your CDI and hypothyroidism could affect any or all of these things depending on what kind of tumor it was, how it was treated, and so forth.

CDI itself does not interfere with the ability to get pregnant and have normal children. However, the eosinophilic granuloma that probably caused your CDI may also have destroyed other pituitary hormones that are necessary for fertility. That has probably happened if you do not have normal menstrual periods.

It is not necessarily abnormal for a girl of 16 to have irregular periods, particularly if she is very active and/or underweight. However, if the menstrual irregularity persists for another year or two, it would be a good idea to investigate the possibility that the pathologic process that caused the CDI (for example, neurosarcoid) has also interfered with the production of other pituitary hormones that affect her ovaries and therefore, her menstrual periods. There are some fairly simple tests that an endocrinologist can do to look for these problems. If these other hormones, called LH (luteinizing hormone), FSH (follicle stimulating hormone) and prolactin are abnormal, there are treatments which can correct them or at least give her normal menstrual periods. When the time comes that she wants to get pregnant, other types of treatment will be needed. These treatments are not routine, will vary from case to case, and should be given only by experts in infertility. The ability to nurse could also be impaired by abnormalities in prolactin or another pituitary hormone, known as oxytocin. This is more difficult to treat and is best dealt with by bottle-feeding. If oxytocin is abnormal, labor and delivery may also be impaired, but the obstetrician can easily correct this problem by giving an infusion of the hormone.

The treatment of CDI in the post-partum state is essentially the same as in other conditions provided the patient is conscious and able to take fluids by mouth. DDAVP may be given by nasal spray, tablets, or injection. If CDI is due to Sheehan’s syndrome (pituitary necrosis), it may also be necessary to treat anterior pituitary hormone deficiencies. In any case, water balance should be monitored closely until it is clear that the patient’s thirst and fluid intake are regulated appropriately.

The ability to nurse could be impaired by abnormalities in prolactin or another pituitary hormone called oxytocin. This is more difficult to treat and is best dealt with by bottle-feeding. If oxytocin is abnormal, labor and delivery may also be impaired but the obstetrician can easily correct this problem by giving an infusion of the hormone.

Neither CDI nor dDAVP treatment is risky for the fetus. As far as we know, dDAVP is completely safe during pregnancy. It has not been associated with any significant increase in spontaneous abortions or fetal malformations. The only risk is water intoxication but that is no greater than in any other patient with CDI and can be avoided by remembering to drink only when you are truly thirsty. Serum sodium is normally lower during pregnancy, so the laboratory criteria for water intoxication are different than in the nonpregnant state.