$Unique_ID{BRK03283} $Pretitle{} $Title{phenobarbital} $Subject{Barbita Vortech Solfoton Poythress Barbiturate sedative anticonvulsant phenobarbital convulsions anxiety tension sleep barbiturates central nervous system brain spinal cord depressants} $Volume{} $Log{} Copyright (C) 1993 Publications International, Ltd. phenobarbital ------------------------------------------------------------------------------ BRAND NAMES (Manufacturers) Barbita (Vortech) phenobarbital (various manufacturers) Solfoton (Poythress) TYPE OF DRUG Barbiturate sedative and anticonvulsant INGREDIENT phenobarbital DOSAGE FORMS Tablets (8 mg, 16 mg, 32 mg, 65 mg, and 100 mg) Capsules (16 mg) Oral liquid (15 mg and 20 mg per 5-ml spoonful, with 13.5% alcohol) STORAGE Phenobarbital tablets and capsules should be stored at room temperature in tightly closed containers. The oral liquid should be stored at room temperature in a tightly closed, light-resistant container. Phenobarbital liquid should not be used if the solution becomes cloudy--it is no longer effective. This medication should never be frozen. USES Phenobarbital is used to control convulsions, to relieve anxiety or tension, and to promote sleep. Phenobarbital belongs to a group of drugs known as barbiturates. The barbiturates are central nervous system (brain and spinal cord) depressants. TREATMENT In order to avoid stomach irritation, you should take phenobarbital with food or with a full glass of water or milk. The oral liquid should be measured carefully with a specially designed 5-ml measuring spoon. An ordinary kitchen teaspoon is not accurate enough. The liquid dose can be taken by itself or diluted with water, milk, or fruit juice. If phenobarbital is being taken as a sleeping aid, take it 30 to 60 minutes before you want to go to sleep. If you are taking this medication for the treatment of seizures, phenobarbital works best when the level of medicine in your bloodstream is kept constant. It is best, therefore, to take the doses at evenly spaced intervals day and night. For example, if you are to take three doses a day, the doses should be spaced eight hours apart. If you are taking this medication on a regular basis and you miss a dose, take the missed dose as soon as you remember. However, if it is almost time for your next dose, do not take the missed dose at all; just return to your regular dosing schedule. Do not double the next dose. If you are taking this medication to control seizures and you miss more than two doses, be sure to contact your doctor immediately. SIDE EFFECTS Minor. Constipation, diarrhea, dizziness, drowsiness, a "hangover" feeling, headache, nausea, stomach upset, or vomiting. These side effects should disappear as your body adjusts to the medication. If you feel dizzy or light-headed, sit or lie down for a while; get up slowly from a sitting or reclining position, and be careful on stairs. To relieve constipation, increase the amount of fiber in your diet (fresh fruits and vegetables, salads, bran, and whole-grain breads), exercise, and drink more water (unless your doctor directs you to do otherwise). Major. Tell your doctor about any side effects that are persistent or particularly bothersome. IT IS ESPECIALLY IMPORTANT TO TELL YOUR DOCTOR about chest tightness, confusion, depression, difficulty in breathing, excitation, fatigue, feeling faint, hives or itching, loss of coordination, muscle or joint pain, skin rash, slurred speech, sore throat, unusual bleeding or bruising, unusual weakness, or yellowing of the eyes or skin. INTERACTIONS Phenobarbital interacts with other types of medications: 1. Concurrent use of it with other central nervous system depressants (such as alcohol, antihistamines, benzodiazepine tranquilizers, muscle relaxants, narcotics, pain medications, phenothiazine tranquilizers, and sleeping medications) or with tricyclic antidepressants can cause extreme drowsiness. 2. Valproic acid, chloramphenicol, and monoamine oxidase (MAO) inhibitors can prolong the effects of the barbiturates. 3. Phenobarbital can increase the elimination from the body (thereby decreasing the effectiveness) of oral anticoagulants (blood thinners, such as warfarin), digitoxin, tricyclic antidepressants, cortisone-like medications, doxycycline, metronidazole, quinidine, oral contraceptives (birth control pills), estrogen-containing drugs, phenytoin, acetaminophen, and carbamazepine. 4. Phenobarbital can decrease the absorption of griseofulvin from the gastrointestinal tract. 5. The combination of phenobarbital and furosemide can cause low blood pressure and fainting. 6. Phenobarbital can increase the side effects of cyclophosphamide or large doses of acetaminophen. BE SURE TO TELL YOUR DOCTOR about any medications you are currently taking, especially any listed above. WARNINGS * Tell your doctor about unusual or allergic reactions you have had to any medications, especially to phenobarbital or other barbiturates (such as amobarbital, butabarbital, mephobarbital, pentobarbital, primidone, and secobarbital). * Tell your doctor if you now have or if you have ever had acute or chronic (long-term) pain, Addison's disease (caused by an underactive adrenal gland), diabetes mellitus, kidney disease, liver disease, lung disease, mental depression, porphyria, or thyroid disease. * Before having surgery or any other medical or dental treatment, tell your doctor or dentist you are taking this drug. * If this medication makes you dizzy or drowsy, do not take part in any activity that requires alertness, such as driving a car or operating potentially dangerous machinery. * This drug has the potential for abuse and must be used with caution. Tolerance to the medication develops quickly; do not increase the dosage or stop taking this drug unless you first consult your doctor. If you have been taking this drug for a long time or have been taking large doses of it, you may experience anxiety, muscle twitching, tremors, weakness, dizziness, nausea, vomiting, insomnia, or blurred vision when you stop taking it. Your doctor may, therefore, want to reduce your dosage of this medication gradually. * Some of these products contain the color additive FD&C Yellow No. 5 (tartrazine), which can cause allergic-type reactions (rash, fainting, difficulty in breathing) in certain susceptible individuals. * Be sure to tell your doctor if you are pregnant. Phenobarbital crosses the placenta, and birth defects have been associated with the use of this medication during pregnancy. If phenobarbital is used during the last three months of pregnancy, there is a chance that the infant will be born addicted to the medication and will experience a withdrawal reaction (seizures or irritability) at birth. The infant could also be born with bleeding problems. The risks and benefits of treatment should be discussed with your doctor. Also, tell your doctor if you are breast-feeding an infant. Small amounts of phenobarbital pass into breast milk. ---------------- The material contained here is "FOR INFORMATION ONLY" and should not replace the counsel and advice of your personal physician. Promptly consulting your doctor is the best path to a quick and successful resolution of any medical problem.