(contains a fixed combination of isoniazid, isoniazid, and pyrazinamide)WHY is this medication prescribed ?
Isoniazid is an antibiotic that eliminates the bacteria that cause tuberculosis (TB). It is generally used in combination
with other drugs to treat TB and to prevent it in people who have had contact with the TB bacteria.
HOW should this drug be taken ?
Isoniazid is commercially available as 100 mg or 300 mg white tablets and is usually taken once a day.
Isoniazid works best on an empty stomach (one hour before or two hours after a meal.)
If you take aluminum hydroxide gel (e.g., Amphojel) which is an antacid, take it at least 1 hour after taking isoniazid.
Rarely, the intravenous form of isoniazid may be used (e.g. in patients who have problems absorbing the oral form of isoniazid). The intravenous form of isoniazid is an investigational drug in Canada.
Isoniazid must be taken regularly to be effective. Take all of your doses even if you begin to feel better after a few
weeks. To avoid missing doses, try to take this medication at the same time that you perform other regular daily activity, such as brushing your teeth at bedtime.
What should you do if you FORGET a dose?
If you miss a dose of isoniazid, take it as soon as possible. If you remember your missed dose close to the time for
your next dose, then take only the regularly scheduled dose. Do not double your dose.
What ADVERSE EFFECTS can this drug cause ? What should you do about them?
Isoniazid can sometimes cause nausea, vomiting, or loss of appetite. Although isoniazid works best on an empty
stomach, adverse stomach effects may be relieved by taking it with a snack. If these effects remain bothersome, please call the clinic or discuss them at your next visit.
Isoniazid may cause tingling, prickling, burning, tightness, pulling, and drawing feeling the hands and feet. Contact your
physician if you experience any of these symptoms. Your doctor may prescribe pyridoxine (vitamin B6) to treat or prevent this problem.
Occasionally, other adverse effects such as rash, fever, swollen glands, or feeling tired or weak may occur. If these
effects occur and are bothersome, please call the clinic or discuss them at your next visit.
In rare cases, isoniazid can cause vision problems or eye pain. Contact your doctor if this occurs.
IT IS IMPORTANT THAT YOU KEEP YOUR DOCTOR AND LABORATORY APPOINTMENTS, SO THAT YOUR PROGRESS CAN BE ASSESSED REGULARLY.
IF YOU ARE EXPERIENCING ANY ADVERSE EFFECTS, PLEASE DISCUSS THEM WITH YOUR HEALTH CARE TEAM.
What other PRECAUTIONS should you follow while using this drug ?
You should not stop taking this medication, even if you feel better and have no symptoms, unless you are told to stop by your doctor.
Before taking isoniazid, tell your doctor if you ever were treated for tuberculosis, or had a bad reaction to isoniazid.
Inform your health care team if you have a history of kidney or liver disease, diabetes, or alcoholism.
Isoniazid can interact with other drugs. Therefore, inform your doctor and pharmacist about all the prescription and
non-prescription medications you are taking, especially aluminum hydroxide gel (antacids), disulfiram (Antabuse), and
phenytoin (Dilantin). Do not start taking other medications without discussing it first.
Diabetics should not use Clinitest to test their urine for sugar because isoniazid can cause false results in this test.
Please inform your doctor or pharmacist if you are pregnant or breast-feeding.
How should this medication be STORED?
Isoniazid should be stored in a cool (15-30C), dry place. It should be kept out of the reach of children.
Do not store in your bathroom as heat and moisture may cause the medication to lose potency.
IF YOU HAVE ANY QUESTIONS OR CONCERNS ABOUT THIS MEDICATION, PLEASE DISCUSS THEM WITH YOUR
NURSE, PHARMACIST, OR PHYSICIAN.
PLEASE WRITE DOWN YOUR QUESTIONS OR CONCERNS TO ENSURE THEY ARE ADDRESSED
