Precautions:
Before taking phenobarbital, tell your doctor or pharmacist if you are allergic to it; or to other barbiturates (such as primidone, secobarbital); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: certain hormone problems (adrenal disease such as Addison’s disease), liver problems, kidney problems, lung disease (such as sleep apnea, chronic obstructive pulmonary disease-COPD), mental/mood disorders (such as depression, thoughts of suicide), history of alcohol/substance abuse, personal/family history of a certain blood disorder (porphyria), certain vitamin deficiencies (folic acid, vitamin K).
This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages.
The liquid form of this product may contain alcohol or sugar. Caution is advised if you have diabetes, alcohol dependence, liver disease, or any other condition that requires you to limit/avoid these substances in your diet. Ask your doctor or pharmacist about using this product safely.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Older adults may be more sensitive to the side effects of this drug, especially drowsiness and dizziness. However, this drug can often cause excitement or confusion instead of drowsiness in older adults. Drowsiness, confusion, and dizziness can increase the risk of falling.
Children may be more sensitive to the side effects of the drug. This drug can often cause excitement instead of drowsiness in young children.
This medication is not recommended for use during pregnancy. It may harm an unborn baby. However, since untreated seizures are a serious condition that can harm both a pregnant woman and her unborn baby, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately talk to your doctor about the benefits and risks of using this medication during pregnancy. Since birth control pills, patches, implants, and injections may not work if taken with this medication (see also Drug Interactions section), discuss reliable forms of birth control with your doctor.
This medication may lower your folic acid and vitamin K levels, increasing the risk of spinal cord defects. Therefore, check with your doctor to make sure you are taking enough folic acid and vitamin K. Infants born to mothers who have been using this medication during pregnancy may also have symptoms such as fussiness, shaking, or bleeding. Tell the doctor immediately if you notice any of these symptoms in your newborn.
This medication passes into breast milk and may cause excessive sleepiness or feeding problems in the nursing infant. Consult your doctor before breast-feeding.
Interactions:
Some products that may interact with this drug include: darunavir, etravirine, felbamate, rilpivirine, MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine), phenothiazines (such as chlorpromazine, prochlorperazine).
Other medications can affect the removal of phenobarbital from your body, which may affect how phenobarbital works. Examples include disulfiram, phenytoin, valproic acid, St. John’s wort, among others.
This medication can speed up the removal of other medications from your body, which may affect how they work. Examples of affected drugs include cobicistat, cyclosporine, doxycycline, estrogens, griseofulvin, metronidazole, ranolazine, voriconazole, “blood thinners” such as warfarin, corticosteroids such as prednisone, calcium channel blockers such as felodipine/nimodipine, among others.
This medication may decrease the effectiveness of hormonal birth control such as pills, patch, or ring. This could cause pregnancy. Discuss with your doctor or pharmacist if you should use additional reliable birth control methods while using this medication. Also tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your birth control is not working well.
The risk of serious side effects (such as slow/shallow breathing, severe drowsiness/dizziness) may be increased if this medication is taken with other products that may also affect breathing or cause drowsiness. Therefore, tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, antihistamines (such as cetirizine, diphenhydramine), tricyclic antidepressants (such as amitriptyline), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, and narcotic pain relievers (such as codeine).
Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
Phenobarbital is very similar to primidone. Do not use medications containing primidone while using phenobarbital.
