Sometimes the adverse effect of the antibiotic is related to the dose administered and this require precise dose calculation before administering the antibiotic to the patient especially in case of injection because the amount that reach the blood is higher than oral administered antibiotics. Calculating the antibiotic dose per kilogram of patient body weight is the best solution to avoid this problem.

The third type of adverse effect of antibiotics is due to the amplification of the body reaction against some antibiotic substances. Some patients may develop allergic reactions against certain types of antibiotics and this side effect could be treated easily through performing a simple allergy test before starting the course of treatment to find out whether the body can tolerate the antibiotic substance or not. If the patient develops skin rashes then the antibiotic should be replaced with another to avoid more serious allergic reactions.

Another serious side effect which is related to the dose of antibiotics is the toxicity. Toxicity is now thought to be one of the most serious side effects of antibiotics and doctors should pay extra care for dose calculation of the administered antibiotic especially in patients who do not normal body condition. Patients who suffer from kidney dysfunction are not able to eliminate the metabolites of the antibiotic substance, those who suffer from liver disease also are not able to completely degrade antibiotic. Patients who suffer from immunosuppressive diseases like HIV and AIDS may suffer from the same adverse side effects.