Question: Why is it that penicilin causes my white blood cell count to lower, therby causing meningitus?

Andrew Swale answered on 22 Jun 2013:

Typically, antibiotics such as penicillin do not actively lower white blood cell count

However, it may seem this way as when given antibiotics you usually have some sort of infection and therefore your white cell count has risen. Therefore the antibiotics assist in fighting the infection and once eradicated your white cell count will have lowered (however this should still be a normal level)

You are indeed correct that a low white cell count can increase the risk of developing meningitis