Examination Counseling for Licensed Pharmacists: Drugs Affecting the Synthesis of protein

Drugs that affect the synthesis of protein

vinblastine

There are mainly vinblastine (VLB) and vincristine (VCR), which are alkaloids contained in Catharanthus roseus of Apocynaceae.

"Pharmacological action" can stop cell mitosis at metaphase. The inhibitory effect of VLB on mitosis is stronger than that of VCR, but the latter is irreversible. The mechanism of action is that drugs bind to spindle filament tubulin, which denatures it, thus affecting microtubule assembly and spindle filament formation. It is a drug that acts on M phase.

"Adverse reaction" VLB can cause bone marrow suppression, leukopenia and thrombocytopenia. And hair loss and nausea. Occasionally have peripheral nerve symptoms. Thrombophlebitis caused by intravenous stimulation. VCR has no obvious inhibitory effect on bone marrow, which mainly causes nervous system symptoms, such as numbness of fingers and toes, slow or disappearance of tendon reflex, peripheral neuritis and so on.

"Clinical application" VLB is mainly used for acute leukemia, Hodgkin's disease and choriocarcinoma. VCR is effective in treating children's acute lymphoblastic leukemia. Usually used in combination with prednisone to induce remission. It is also effective for lymphoma and is often used in combination with other types of anticancer drugs to treat various cancers.

podophyllotoxin

Podophyllotoxin is the effective component of Tibetan plant Podophyllum, and etoposid (vepesid, VP 16) was obtained through transformation and semi-synthesis. Podophyllotoxin can bind to tubulin and destroy the formation of spindle filament. But VP 16 is different. It can interfere with DNA topoisomerase and prevent DNA replication.

Although VP 16 alone is also effective, it is often used in combination with cisplatin to treat lung cancer and testicular tumors with good results. It is also used to treat lymphoma. Similar drug podophyllotoxin glycoside (VM26) is effective in treating brain tumors.

Adverse reactions include bone marrow suppression and gastrointestinal reactions.

Cefotaxil

Cephalotaxine is extracted from the branches, leaves and bark of Cephalotaxus fortunei. Its mechanism is to inhibit the initial stage of protein synthesis, decompose ribosomes and release new peptide chains, but it has no inhibitory effect on the binding of mRNA or tRNA to ribosomes.

It is effective for acute myeloid leukemia and acute monocytic leukemia. Only for slow intravenous drip. Adverse reactions include leukopenia and gastrointestinal reactions, as well as increased heart rate and myocardial ischemia.

L- asparaginase

L- asparagine is an important amino acid, and some tumor cells can't synthesize it by themselves, so they need to take it from outside the cell. L- asparaginase can hydrolyze serum asparagine, which makes tumor cells lack the supply of asparagine and inhibits their growth. Normal cells can synthesize asparagine, which is less affected. Mainly used for acute lymphoblastic leukemia, the remission rate is about 60%, but it is not lasting. Common adverse reactions include gastrointestinal reactions and mental symptoms. There may also be low plasma protein and bleeding. Occasionally allergic reaction, skin test should be done.