The Centers for Disease Control and Prevention and other professional organizations state that breastfeeding should not be discouraged in women taking isoniazid. Nursing mothers who are taking isoniazid should take 25 mg of oral pyridoxine daily.[1,2] Because of the low levels of isoniazid in breastmilk and safe administration directly to infants, it is unlikely to cause adverse reactions in infants, but infants should be monitored for rare instances jaundice. Giving the maternal once-daily dose before the infant's longest sleep period will decrease the dose the infant receives. The amount of isoniazid in milk is insufficient to treat tuberculosis in the breastfed infant. If breastfed infants are treated with isoniazid, they should also receive pyridoxine 1 mg/kg daily.[3]

High-resolution measurement of medication adherence is essential to personalized drug therapy. A US Food and Drug Administration (FDA)-cleared device, using an edible ingestion sensor (IS), external wearable patch, and paired mobile device can detect and record ingestion events. Oral medications must be combined with an IS to generate precise "digitized-medication" ingestion records. We developed a Good Manufacturing Practice protocol to repackage oral medications with the IS within certified Capsugel capsules, termed co-encapsulation (CoE). A randomized bioequivalence study of CoE-IS-Rifamate (Isoniazid/Rifampin 150/300 mg) vs. native-Rifamate was conducted in 12 patients with active Mycobacterium tuberculosis and demonstrated bioequivalence using the population method ratio test (95% confidence interval). Subsequently, CoE-IS-medications across all biopharmaceutical classes underwent in vitro dissolution testing utilizing USP and FDA guidelines. CoE-IS medications tested met USP dissolution specifications and were equivalent to their native formulations. CoE combines oral medications with the IS without altering the quality of the native formulation, generating "digitized" medications for remote capture of dosing histories.

The treatment of tuberculosis requires at least two drugs to retard the development of drug resistance. Unfortunately, patients may take only one drug (monotherapy) when more than one is prescribed. Fixed-dose combinations with two or more antituberculous drugs in one capsule or tablet are available to prevent this. In the United States, these drugs are Rifamate (Marion Merrell Dow), which contains isoniazid plus rifampin, and Rifater (Marion Merrell Dow), which contains isoniazid plus rifampin and pyrazinamide. Because these preparations make monotherapy impossible, they are clearly preferable to individual drugs. In the United States in 1993, however, only 15% to 18% of rifampin was sold in the form of fixed-dose combinations. To correct this deficiency, fixed-dose combinations should be widely promoted and accepted as a primary way to prevent drug-resistant tuberculosis. There are two caveats regarding these preparations. First, many fixed-dose combinations, especially those in developing countries, achieve inadequate blood levels of one or more of the component drugs, especially rifampin. Our recommendations apply only to preparations with proven bioavailability. Second, because the name Rifamate is similar to the name rifampin, mistakes in prescribing and dispensing can result in the patient receiving rifampin alone when Rifamate is intended. A name change from Rifamate to a highly distinctive name such as Rif-Isoniazid is needed to prevent such occurrences.