RIFINAH Coated tablet Ref.[10703] Active ingredients: Isoniazid Rifampicin Rifampicin and Isoniazid

For oral administration.

Another antituberculosis drug may be given concurrently with Rifinah until the susceptibility of the infecting organism to rifampicin and isoniazid has been confirmed.

Adults

Patients should be given the following single daily dose preferably on an empty stomach at least 30 minutes before a meal or 2 hours after a meal:

Rifinah 150: Patients weighing less than 50 kg – 3 tablets.

Rifinah 300: Patients weighing 50 kg or more – 2 tablets.

Use in the elderly

Caution should be exercised in such patients especially if there is evidence of liver impairment.

Signs and Symptoms

Rifampicin

Nausea, vomiting, abdominal pain, pruritus, headache and increasing lethargy will probably occur within a short time after acute ingestion; unconsciousness may occur when there is severe hepatic disease. Transient increases in liver enzymes and/or bilirubin may occur. Brownish-red or orange colouration of the skin, urine, sweat, saliva, tears and faeces will occur, and its intensity is proportional to the amount ingested. Facial or periorbital oedema has also been reported in paediatric patients. Hypotension, sinus tachycardia, ventricular arrhythmias, seizures and cardiac arrest were reported in some fatal cases.

The minimum acute lethal or toxic dose is not well established. However, nonfatal acute overdoses in adults have been reported with doses ranging from 9 to 12 g rifampicin. Fatal acute overdoses in adults have been reported with doses ranging from 14 to 60 g. Alcohol or a history of alcohol abuse was involved in some of the fatal and nonfatal reports. Nonfatal overdoses in paediatric patients ages 1 to 4 years old of 100 mg/kg for one to two doses have been reported.

Isoniazid

Isoniazid overdosage produces signs and symptoms within 30 minutes to 3 hours after ingestion. Nausea, vomiting, dizziness, slurring of speech, blurring of vision, and visual hallucinations (including bright colours and strange designs) are among the early manifestations. With marked overdosage, respiratory distress and CNS depression, progressing rapidly from stupor to profound coma are to be expected, along with severe, intractable seizures. Severe metabolic acidosis, acetonuria and hyperglycaemia are typical laboratory findings.

Management

In cases of overdosage with Rifinah, gastric lavage should be performed as soon as possible. Following evacuation of the gastric contents, the instillation of activated charcoal slurry into the stomach may help absorb any remaining drug from the gastrointestinal tract. Antiemetic medication may be required to control severe nausea and vomiting.

Intensive supportive measures should be instituted, including airway patency, and individual symptoms treated as they arise.

If acute isoniazide overdose is suspected, even in asymptomatic patients, the administration of intravenous pyridoxine (vitamin B6) should be considered. In patients with seizures not controlled with pyridoxine, anticonvulsant therapy should be administered. Sodium bicarbonate should be given to control metabolic acidosis. Haemodialysis is advised for refractory cases; if this is not available, peritoneal dialysis can be used along with forced diuresis.

36 months.

Store below 25°C. If it proves necessary to open a blister pack, Rifinah should be dispensed in amber glass or plastic containers. Protect from moisture.

Blister packs of 84 tablets (4 week calendar packs) in cardboard cartons.

Blister material is PVC/PVDC and aluminium foil/PVC.

Any unused medicinal product or waste material should be disposed of in accordance with local requirements.