Malegra 25 mg should not be taken by individuals who are allergic to sildenafil citrate or any other ingredients in the medication. It's also important to avoid consuming alcohol or grapefruit products while taking Malegra 25 mg, as they can interact with sildenafil citrate and increase the risk of side effects. Additionally, Malegra 25 mg should be used with caution in individuals with certain underlying health conditions, such as cardiovascular disease or liver or kidney impairment.