Medication monitoring is done by measuring blood levels of a drug or some aspect of a drug’s effects. Some prescription drugs are very beneficial for health and may even be life saving, yet are very dangerous if even a small overdose is given. Because of this danger, drugs that are associated with severe or life threatening medical effects after a small overdose would not be available for use in medicine without a method by which to monitor their blood levels or their effects. Medication monitoring is a critical tool in the administration of these medications.