These can be divided into five types. First, those which are closely related to the concentration of the drug and are consistent with what is known of its pharmacology. These so-called type A effects are distinguished from type B effects which are unpredictable, usually rare and may be severe. Anaphylaxis is the most obvious of these; other examples include bone-marrow suppression with co-trimoxazole; hepatic failure with sodium valproate; and pulmonary fibrosis with amiodarone. A more comprehensive classification includes reactions type C (chronic effects), D (delayed effects — such as teratogenesis or carcinogenesis) and E (end-of-dose effects —withdrawal effects). Examples of adverse reactions include nausea, skin eruptions, jaundice, sleepiness and headaches.