Conivaptan (Intravenous)

By lowering the levels of a hormone in the body which is tasked with the regulation of salt and water, conivaptan helps to restore a healthy balance of those two substances.

Overview

Conivaptan is a drug which comes in a powder and must be mixed with water before injection so it can be effective in regulating hormone levels in the body. When there is a high level of a specific hormone in the body which is responsible for regulating water and salt levels, that hormone will have a tendency to over-regulate and cause a shortage of sodium and water in the body. Conivaptan helps to restore balance in a situation like this, by reducing the level of the sodium-regulating hormone.

It also triggers a greater urine flow from the body, while ensuring that no excess amounts of sodium are lost in the extra urination.

Condition Treated

  • Hyponatremia (low sodium levels)

Type of Medicine

  • Vasopressin antagonist

Side Effects

Besides the beneficial effects that conivaptan imparts to a patient being treated with it, there is the possibility that some unwanted side effects may also appear. Some of these are relatively mild in nature and will fade away all on their own, while others may be uncomfortable enough for a patient that your doctor must be informed so that some kind of treatment can be considered. It's also possible that if your side effects are severe enough, your doctor may want to modify your dosage level, or even consider switching to an alternative medication.

Probably the most severe type of side effect that most patients could possibly experience is an allergic reaction, and this falls into the category of very dangerous, possibly life-threatening, reactions. If you should experience any of the following kinds of symptoms, it could be a sign of an allergic reaction, and you should immediately seek medical attention for it:

• Hives
• rashes or redness on the skin
• itching which cannot be alleviated
• skin which becomes blistered, swollen, or peeling
• fever and or chills
• extreme tightness in the chest or in the throat area
• wheezing or other difficulties with breathing
• difficulty with normal talking
• unexplained sudden hoarseness
• extreme swelling in the facial area or in the mouth, lips, throat, or tongue.

In the category of severe side effects which should be mentioned to your doctor, there are the following:

• fast or irregular heartbeat
• increased thirst
• seizures or convulsions
• sensation of being weak or tired
• loss of appetite
• confusion or disorientation
• muscle weakness or cramping
• mood changes which may signal electrolyte or fluid problems
• inability to urinate, or a significant reduction in the amount of urine passed
• dry mouth
• upset stomach
• nausea and/or vomiting
• fever and/or chills
• heartbeat that feels abnormal or is pounding
• extreme dizziness or disorientation
• blood in the urine, which may be a sign of a urinary tract infection
• pain or a burning sensation when urinating
• increased urgency for urination
• unusual need to urinate frequently
• pain in the lower stomach or abdomen
• pelvic discomfort or pain
• unexplained swelling in the arms or legs
• persistent headaches.

Since this is an injectable medication, it is possible that there could be tissue damage if the medication goes beyond the walls of the vein it has been injected into. Make sure to tell your doctor or nurse if you experience any kind of redness, inflammation, or sores in the area where the medication is being injected.

There are some additional side effects which are considered to be fairly mild in nature, and may not call for medical attention unless you consider them to be extremely uncomfortable or painful:

• Irritation in the area around an injection site
• mild headaches
• increased thirst
• constipation or difficulty with bowel movements
• diarrhea
• upset stomach or heartburn
• insomnia
• burning sensation in the throat.

Dosage

Patients will generally not administer conivaptan themselves, instead it will be administered in a hospital setting, by qualified medical personnel. The normal route for insertion into the body is by injecting conivaptan into a vein through an IV drip. The needle will ordinarily be placed into one of your body's larger veins, for instance, one in your upper chest.

Using this procedure, conivaptan will be infused for up to four days at a time, in a more or less constant drip. Since there is a strong possibility of conivaptan irritating the skin around the injection site or the vein itself, an IV needle will need to be relocated to an alternate vein every 24 hours.

While this medication is being administered, frequent bloodwork must be taken, in order to ensure that conivaptan is having the desired effect, and is controlling the sodium levels in the body. Because this medication is always administered in a hospital setting, you'll probably never have to worry about missing a dosage.

Interactions

Conivaptan is known to interact with a large number of drugs, including all of the following:

• digoxin
• anti-malaria medications
• cancer medications – bortezomib, docetaxel, paclitaxel, tamoxifen, busulfan, doxorubicin, vinorelbine, vinblastine, cincristine, exemestane, etoposide, irinotecan, and flutamide
• ergo medications – ergomar, methergine, migranal, cafergot, migergot
• erectile dysfunction medications
• antibiotics – trimethoprim, tetracycline, rifabutin, rifampin, doxycycline
• asthma medications – albuterol, theophylline, fluticasone, Montelukast, budesonide
• anti-depressants
• anti-psychotic medications
• seizure medications
• stomach acid medications – ondansetron, rabeprazole, lansoprazole
• HIV medications – nevirapine, tipranavir, efavirenz
• Diabetes medications – repaglinide, pioglitazone, nateglinide
• Sedatives – clonazepam, diazepam, clorazepate
• Narcotic medications
• Organ transplant rejection medications – cyclosporine, tacrolimus, sirolimus
• Cholesterol-lowering medications – pravastatin, rosuvastatin, atorvastatin, simvastatin, lovastatin
• Blood pressure medications – quinidine, nimodipine, amiodarone, amlodipine, enalapril, isradipine, losartan, disopyramide, nicardipine, nisoldipine
• Beta blockers - bisoprolol

To be sure that you are not taking any medications which might interact with conivaptan, you should prepare a complete list of all medications you are currently taking, including prescription drugs, vitamins, herbal supplements, and over-the-counter drugs. Your doctor will review this list and make a determination whether any of the medications you are taking need to be discontinued or lowered in dosage while you are being treated with conivaptan.

This list will also come in very handy if you should need to make an unscheduled trip to an emergency room or healthcare clinic. Doctors there will be able to review your list of medications and dosages, so they can safely treat you for whatever medical condition brought you to the emergency room.

Warnings

If you know that you are allergic to conivaptan or any of the ingredients used in its manufacture, make sure to tell your doctor about this before treatment. If you discover during treatment that you are allergic to the medication, you should seek immediate medical attention, because symptoms may become severe. You should also inform your doctor if you are allergic to any other medications, foods, substances, or pets. If you suspect that you are experiencing an allergic reaction, write down the symptoms that you are experiencing so that you can discuss them with your doctor.

Once you start taking conivaptan, you may also experience other side effects which are described in the ‘side effects' section of this document. There are a number of medications and drugs that should not be taken in conjunction with conivaptan, and these will be listed under the ‘interactions' section of this document.

If you have difficulty passing urine, or if you have any history of kidney disease or kidney problems, or if you have low blood volume, you may not be a good candidate for taking conivaptan. In any case, you should discuss your medical history with your doctor, so that a determination can be made whether or not conivaptan is the right medication for you.

There are some medical conditions which are deemed to be dangerous for patients who are being treated with conivaptan:

• Persons suffering from malnourishment
• Patients being treated for alcoholism
• Liver disease, or any history of liver problems
• Kidney disease, or any history of kidney problems
• Congestive heart failure

It is not known with certainty whether conivaptan has any impact on an unborn fetus, so if you become pregnant while taking this medication, you should discuss the situation with your doctor. It is also not known whether conivaptan is passed on to a nursing infant through breast milk, and since this is not known, it's safer to not be breastfeeding while taking this medication. If you have any questions or objections about this, it can be discussed and left up to your family doctor.

Make sure to let everyone in your healthcare support network know that you are taking conivaptan. This includes pharmacists, dentists, doctors, and nurses, as well as any home care aides who may be providing care for you.

Some patients have reported a feeling of dizziness or faintness when rising quickly after taking conivaptan, so it is advisable to rise slowly if you have been recently lying down or sitting. For the same reason, you should climb stairs at a careful pace, and make sure of each step as you go.

It is very important that your blood levels are checked whenever your doctor advises it, because these blood level checks will determine whether there is a proper level of sodium in your bloodstream and whether the medication is working properly.

It is possible for there to be severe reactions and even fatality if the sodium-fixing action works too quickly for the body to adapt to it. There is an increased risk of these kind severe reactions in people who have consistently poor nutrition, or who are alcohol abusers. If you fall into any of these categories, you should have a frank discussion with your doctor so that you don't experience these severe reactions.

If you are taking digoxin, make sure to point this out to your doctor, because it is likely he/she will want to monitor your bloodwork much more closely, if you are also taking conivaptan.

It is possible for this medication to cause fertility problems in some patients, and people have been known to become unable to have children after taking conivaptan. Talk to your doctor about the risks of using this medication, compared to the benefits it provides to your system.

Storage

There is no need for you to be concerned about the proper storage of conivaptan, since it will not be issued to you for self-administration at home. It is always administered in a hospital setting by medical professionals, and the drug will be properly stored in the hospital medicine cabinets.

Summary

Conivaptan is an injectable medication which belongs to the class of drugs called vasopressin antagonists, and is used in the treatment of patients who are experiencing a shortage of sodium in their bodies. Since this can lead to more problematic medical conditions, some type of medication must be used to restore the proper balance in the body of sodium and water.

This is not the kind of medication which can be administered at home by the patient himself/herself, and is instead administered in a hospital setting, where professional medical people can do that. It is necessary during treatment to conduct bloodwork tests, in order to determine if conivaptan is producing the desired effect in the body, and increasing the level of sodium.

There are a large number of other drugs which are known to interact with conivaptan, so your doctor will need to carefully review a list of your current medications with you to be sure you can safely take conivaptan.

Patients being treated with conivaptan have reported a fairly wide variety of side effects, ranging from the fairly mild to the severe, so patients and medical people need to be very observant when this medication is being used.