Medication is a process of prescribing medicines by knowledgeable physicians. Medicines which are not prescribed when consumed may generate side effects. Some diseases require more than one drug to control the disease. If drugs are not carefully prescribed adverse reactions may happen. Meny people died due to medical errors in prescribing medicines by medical practitioners based on their experience. For avoiding all these adverse effects, we need a recommendation system or a decision support system for efficiently prescribing medicines. Many parameters need to be considered before prescribing the medicines like patient's age, medical history, side effects of drugs, possible allergies, drug-drug interactions, drug-disease interactions and drug-food interactions. Semantic web provides tools and technologies like ontologies to construct recommendation models and can retrieve data using tools like SPARQL and inference mechanisms to infer new knowledge.