Difference between Catecholamine and non-catecholamine drugs
Before going through difference between Catecholamine and non-catecholamine drugs. have a look of examples of Catecholamine drugs are Adrenaline, Noradrenaline, Dopamine and Isoprenaline and Non-Catecholamines are Amphetamine, Ephedrine, Pseudoephedrine.
| Catecholamines | Non catecholamines |
| Contain hydroxyl groups at position 3 and 4 on the benzene ring | Lack one or both hydroxyl groups on benzene ring |
| Mainly have direct action. Few compounds may have mixed action (like dopamine) | Mainly have indirect or mixed actions and few may have direct action (like phenylephrine) |
| Have high affinity for α and/or β receptors | Have moderate to poor affinity for adrenoceptors |
| Usually have shorter half life because of their rapid metabolism | Have moderate to longer half life as these are degraded slowly |
| Metabolised mainly by MAO or COMT | Poor substrates for MAO and resistant to COMT |
| Usually not effective by oral route and are given parenterally | Most of the drugs are effective orally |
| Being polar drugs, poorly penetrate the CNS and hence have minimal effect on CNS | Easily pass blood brain barrier and produce significant CNS effects |
| Effects are produced even after adrenergic denervation | Loose activity following adrenergic denervation |
| No development of tolerance | Tolerance develops following repeated administration |