Synthesis
The synthesis begins with a modified Strecker reaction using hydrazine and potassium cyanide on arylacetone (1) to give 2. This is then hydrolyzed with cold HCl to give carboxamide 3. More vigorous hydrolysis with 48% HBr cleaves the amide bond and the aryl ether group to produce carbidopa (4). References
External links
Lodosyn prescribing information
Sinemet datasheet for New Zealand
A tracer agent of Indium 111 is injected into a vein where then the tumors absorb the radionuclide Indium 111 and become visible on the scanner. Only the tumors absorb the somatostatin agent Indium 111 making the scan highly effective. Treatment
For symptomatic relief of carcinoid syndrome:
Octreotide (a somatostatin analogue which decreases the secretion of serotonin by the tumor and, secondarily, decreases the breakdown product of serotonin (5-HIAA))
Telotristat ethyl (Xermelo) along with a somatostatin analogue in patients not responding to somatostatin analogue monotherapy. It is a tryptophan hydroxylase inhibitor and reduces the production of serotonin. Peptide receptor radionuclide therapy (PRRT) with lutetium-177, yttrium-90 or indium-111 labeled to octreotate is highly effective
Methysergide maleate (antiserotonin agent but not used because of the serious side effect of retroperitoneal fibrosis)
Cyproheptadine (an antihistamine drug with antiserotonergic effects)Alternative treatment for qualifying patients:

Surgical resection of tumor and chemotherapy (5-FU and doxorubicin)
Endovascular, chemoembolization, targeted chemotherapy directly delivered to the liver through special catheters mixed with embolic beads (particles that block blood vessels), used for patients with liver metastases. Uncertainties
Disease progression is difficult to ascertain because the disease can metastasize anywhere in the body and can be too small to identify with any current technology. Markers of the condition such as chromogranin-A are imperfect indicators of disease progression. Prognosis
Prognosis varies from individual to individual. It ranges from a 95% 5-year survival for localized disease to an 80% 5-year survival for those with liver metastases. The average survival time from the start of octreotide treatment has increased to about 12 years.