Papaverine Apomorphine

The most known narcotics are the opium alkaloids such as morphine, codeine, thebaine, papaverine, noscapine and their derivatives and modified compounds such as nalmorphine, apomorphine, apomopholcodine, dihydrocodeine, hydro-morphone and heroine, also known as diamorphine. Synthetic narcotics share the structural skeleton of morphine and include dextromethorphan, pentazocine, phenazocine meperidine (pethidine), phentanyl, anfentaitil, remifentalin, methadone, dextropropoxyphene, levoproxyphene, dipipanone, dextromoramide, meptazinol and tramadol. Thebaine derivatives are also modified narcotics and include oxycodone, oxymorphone, etorphine, buprenorphine, nalbuphine, naloxone or naltrexone. Narcotics can be semi-synthesized or totally synthesized from the morphine and thebaine model. The compounds serve various purposes in clinical practise. 

A combination of phentolamine with the nonspecific smooth muscle relaxant papaverine, when injected directly into the penis, may cause erections in men with sexual dysfunction. Long-term administration may result in fibrotic reactions. Systemic absorption may lead to orthostatic hypotension priapism may require direct treatment with an -adrenoceptor agonist such as phenylephrine. Alternative therapies for erectile dysfunction include prostaglandins (see Chapter 18), sildenafil and other cGMP phosphodiesterase inhibitors (see Chapter 12), and apomorphine. 

Very recently, it has been observed that oliveroline shows antiparkinsonian activity similar to apomorphine. Oliveridine and oliverine caused a dose-dependent hypotension in normal rats, which was followed by a secondary hypertension. In the isolated rabbit ear, oliveridine had a vasodilating effect compaiable to that of papaverine. All three aporphines were obtained from West African Annonaceae. ... 

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