be administered in therapeutically effective amounts via any of the usual and acceptable modes known in the art either singly or in combination with one or more therapeutic agents a therapeutically effective amount can vary widely depending on the severity of the disease the age and relative health of the subject the potency of the compound used and other factors in general satisfactory results are indicated to be obtained systemically at daily dosages of from about 0 03 to 2 5 mg kg per body weight an indicated daily dosage in the larger mammal e g humans is in the range from about 0 5 mg to about 100 mg conveniently administered e g in divided doses up to four times a day or in retard form suitable unit dosage forms for oral administration comprise from ca 1 to 50 mg active ingredient compounds of the invention can be administered as pharmaceutical compositions by any conventional route in particular enterally e g orally e g in the form of tablets or capsules or parenterally e g in the form of injectable solutions or suspensions topically e g in the form of lotions gels ointments or creams or in a nasal or suppository form pharmaceutical compositions comprising a compound of the present invention in free form or in a pharmaceutically acceptable salt form in association with at least one pharmaceutically acceptable carrier or diluent can be manufactured in a conventional manner by mixing granulating or coating methods for example oral compositions can be tablets or gelatin.