The safety of Nelfinavir was studied in over 1500 patients who received drug either alone or in combination with nucleoside analogues. The majority of adverse events were of mild intensity. The most frequently reported adverse event among patients receiving Nelfinavir was diarrhoea, which was generally of mild to moderate intensity. Adverse events occurring in less than 2% of patients receiving Nelfinavir in all phase II/III clinical trials and considered at least possibly related or of unknown relationship to treatment and of at least moderate severity are listed below.General: Abdominal pain, accidental injury, allergic reaction, asthenia, back pain, fever, headache, malaise, pain and redistribution/accumulation of body fat.Digestive system: Anorexia, dyspepsia, epigastric pain, gastrointestinal bleeding, hepatitis, mouth ulceration, pancreatitis and vomiting.Haemic/Lymphatic system: Anaemia, leukopenia and thrombocytopenia.Metabolic/Nutritional: Increase in alkaline phosphate, amylase, creatinine phosphokinase, lactic dehydrogenase, SGOT, SGPT and g glutamyl transpeptidase, hyperlipaemia, hyperuricaemia, hyperglycaemia, hypoglycaemia, dehydration and liver function tests abnormal.Musculoskeletal system: Arthralgia, arthritis, cramps, myalgia, myasthenia and myopathy.Nervous system: Anxiety, depression, dizziness, emotional lability, hyperkinesia, insomnia, migraine, paraesthesia, seizures, sleep disorder, somnolence and suicide ideation.Respiratory system: Dyspnoea, pharyngitis, rhinitis and sinusitis.Skin/Appendages: Dermatitis, folliculitis, fungal dermatitis, maculopapular rash, pruitus, sweating, and urticaria.Ophthalmic: Acute iritis and eye disorder.Urogenital system: Kidney calculas, sexual dysfunction.