Review Question - QID 104886

The clinical presentation is consistent with a peripheral neuropathy, likely due to a vitamin B6 deficiency associated with isoniazid (INH) treatment.

Peripheral neuropathy is a known complication of treatment with isoniazid, as is hepatitis. Concomitant administration of pyridoxine (vitamin B6) has been shown to prevent and decrease the symptoms associated with it including numbness, tingling, ataxia, and CNS difficulties. For prevention and treatment of isoniazid-induced peripheral neuropathy, pyridoxine is employed.

Inge and Wilson discuss the recommended treatment strategies in a recent review of initial tuberculosis (TB) management and conclude, "combination therapy with isoniazid, rifampin, pyrazinamide, and ethambutol should be promptly initiated for a two-month intensive phase." In most cases this is followed by isoniazid and a rifamycin product for a four- to seven-month "continuation phase."

Blumberg et al. report that while the most serious complication of INH treatment is hepatitis, the most visible and concerning is that of peripheral neuropathy, especially in patients "predisposed to neuropathy (such as patients with diabetes, uremia, malnutrition, and HIV infection), pregnant women, and persons with seizure disorders." They recommend pyridoxine to be administered with INH to prevent the development of peripheral neuropathy.

Incorrect Answers:
Answer 1: The symptoms of vitamin A (beta-carotene) deficiency include night blindness, xerophthalmia, and faulty bone formation.
Answer 2: Vitamin B1 (thiamine) deficiency can cause dry and wet beriberi.
Answer 3: Vitamin B3 (niacin) deficiency most notably causes pellagra: dermatitis, diarrhea, dementia, and eventually death.
Answer 5: Vitamin B12 (cobalamin) deficiency most commonly causes a megaloblastic anemia with neurologic symptoms.