There was one patient who suffered an intracranial bleed. This baby had a normal coagulation profile (INR of 1.2), a normal platelet count (427*109/L) and also received vitamin k at birth. 3/26 (11.5%) patients had an INR of >1.0. Two of them had a post circumcision bleed. One had factor X deficiency and another kid had factor VII, IX and X deficiency which are vitamin K dependent factors. These babies responded to vitamin K therapy. This might be because of rifampicin induced coagulopathy due to vitamin K deficiency. Anti-tuberculosis medication can induce thrombocytopenia and coagulopathy which is mostly due to rifampicin. The pathogenesis of rifampicin-induced vitamin K deficiency is most likely to be multifactorial. It can be because of impairment of vitamin K production from gut flora due to intestinal decontamination or may be due to oxidative degradation of vitamin K as a result of hepatic microsomal enzyme stimulation. Chen et al. reported rifampicin induced disseminated intravascular coagulation (DIC) in a 22 year old boy treated for pulmonary Tuberculosis at the West China Hospital. Sampaziotis et al. also revealed rifampicin induced severe coagulopathy in patients with primary sclerosing cholangitis and refractory pruritus. Kang et al. observed a case of a 68-year-old woman developing an acute subdural hemorrhage secondary to rifampicin induced thrombocytopenia. According to the literature, rifampicin-induced thrombocytopenia usually occurs in high dose intermittent treatment because neutralizing antibodies form during continuous daily treatment. It is important to start treatment early in cases of drug-induced thrombocytopenia to prevent morbidity and mortality. In our study we observed coagulopathy however none of the newborns experienced thrombocytopenia. This could suggest that maybe instead of using both rifampicin and isoniazid as chemoprophylaxis; we can use only isoniazid to decrease the chance of thrombocytopenia, coagulopathy and bleeding. However, considering the nature of study and small sample size we can't establish its temporality and causation.
There is very little data on BCG vaccination overdose in Pakistan. Moreover, medical errors tend to be underreported. By reporting these medical errors and following-up on the patients we can better understand the consequences of the medical error and their management. It also emphasizes on having checks to prevent medical errors like this in the future by increasing the awareness of health care staff. Small sample size and single centered retrospective nature are the major limitations of our study.