The side effect of decrease in body weight caused by the alkylphosphocholines such as miltefosine can be antagonized by certain acetylcholine receptor antagonists such as domperidone and pimozide. The combination of alkylphosphocholine plus the antagonist does not have any effect on the anti-tumor action of the alkylphosphocholine. The combination also caused no new side effects in the animals.

The side effect of decrease in body weight caused by the alkylphosphocholines such as miltefosine can be antagonized by certain acetylcholine receptor antagonists such as domperidone and pimozide. The combination of alkylphosphocholine plus the antagonist does not have any effect on the anti-tumor action of the alkylphosphocholine. The combination also caused no new side effects in the animals.

The invention relates to imidazole derivatives of the general formula (I) ##STR1## wherein Im represents an imidazolyl group of formula: ##STR2## A represents the group CH or a nitrogen atom; R.sup.1 and R.sup.2, which may be the same or different, and may be attached to either the same or different fused rings of the naphthalene moiety, each represents a hydrogen atom, a halogen atom, or a hydroxy, C.sub.1-4 alkoxy, C.sub.1-4 alkyl or C.sub.1-4 alkylthio group, and one of R.sup.1 and R.sup.2 may also represent a group --NR.sup.3 R.sup.4 (wherein R.sup.3 and R.sup.4, which may be the same or different, each represents a hydrogen atom or a C.sub.1-4 alkyl group, or together with the nitrogen atom to which they are attached form a saturated 5 to 7 membered ring); n represents 1, 2 or 3; R.sup.5, R.sup.6, R.sup.7, are as defined in the specification; and physiologically acceptable salts and solvates thereof.