Total compliance is necessary. Many patients think that if they miss a few  of the tablets each week it does not really matter. Analogies are useful here: for example, if a female is using oral  contraception she may become pregnant if only one pill is missed. In acne treatment, failure to take the tablets correctly and to use the topical therapy adequately will  markedly reduce  the  rate of response. Certain antibiotics (in particular tetracycline and erythromycin) are less adequately absorbed if taken with food and after food; it is therefore important to take these tablets hour before food, with a sip of water and not with milk. These points must be emphasized.