CHEMOTHERAPY DRUGS AND MECANISM

ANTI BACTERIAL DRUGS

S.NO

Drug

Isolate From

Acting On

Type of Activity

Site Of Action

Mechanism

Unwanted Effect

1.

Penicillins (ẞ-lactam antibiotics)

Penicillum

Bacteria

Bacteriostatic & lytic) (Broad Spectrum) Act on gram +ve and  -ve

Cell wall

Block transpeptidase which is responsible for cross linking of cellwall&activates autolysis(degradative enzymes),binds penicllin binding proteins and inhibit cell wall synthesis

Hypersensitivity (due to degradation Products of Penicillin),skin rashes,fever,Git disturbances)

2

Cephalosporins/ Cephamycins

Cephalosporium fungus/Streptomyces

Bacteria

Bacteriostatic & lytic) (Broad Spectrum) Act on gram +ve and  -ve

Cell wall

Similarly as Penicillins By inhibiting cell wall synthesis

Hypersensitivity Cefradine-Nephrotoxicity Cefoperazone-Diarrhoea

3

Tetracyclins

-

Bacteria

Bacteriostatic & lytic) (Broad Spectrum) Act on gram +ve and  -ve

Cell Wall

Inhibit Protein Synthesis by binding to 30s ribosomes-preventing the binding of aminoacyl t-RNA to m-Rna

Git Disturbances, Vit-B complex Deficiency,staining of teeth and hypoplasia and bone deformities due to chelate Ca,hepatotoxic in Pregnant,Vestibular disturbances.

4

Aminoglycosides

-

Bacteria

Bacteriostatic & lytic) (Broad Spectrum) Act on gram +ve and  -ve

Cell Wall

Binds to 30s &50s subunits and cause misreading the codon message of m-RNA

Idiosyncratic bone marrow depression,pancytopenia Grey baby syndrome in new borns ,hypersensitivity,nausea, Vomiting.

5.

Chloramphenicol

Streptomyces cultures

Bacteria

Bacteriostatic & lytic) (Broad Spectrum) Act on gram +ve and  -ve

Cell Wall

Binds to 50s subunit and interferes with peptide bond formation& transfer of Peptidechain from  p-site(inhibition of trans peptidation)

Idiosyncratic bone marrow depression,pancytopenia Grey baby syndrome in new borns ,hypersensitivity,nausea, Vomiting.

6.

Macrolides Erythromycin

-

Bacteria

Bacteriostatic & lytic) (Broad Spectrum) Act on gram +ve and  -ve

Cell Wall

Binds to 50 s subunit and inhibit protein synthesis (inhibit translocation)

GIT disturbances, Hypersensitivity.rashes, Fever,transient hearing Disturbances

7.

Sulfonamides

-

Bacteria

Narrow Spectrum and  Bacterio static

Cell wall

Paba antimetabolite inhbit dihydropteroate synthetase also inhibits union of paba and pteridine which conjugate with glutamic acid to form dhf

Nausea,vomiting Mental disturbances, Hepatits,hypersensitivity, Bone marrow depression,crystalluria.

8.

Trimethoprim

-

Bacteria

Narrow Spectrum and  Bacterio static

Cell wall

Inhibits DHF reductase theree by inhibiting the formation of THF which is useful in synthesis of purines

Nausea,vomiting,blood disorders,skin rashes.Megaloblastic anaemia.

9.

Cotrimoxazole

-

Bacteria

(sulphamethoxazole+ Trimethoprim)5:1 Ratio

Cell Wal

-

-

10

Polymixine

-

-

Have high affinity for phospolipids, Components of cell Membranes of bacteria& disrupts their osmotic properties

ANTI- TUBERCULAR DRUGS

1

Isoniazide

-

Inhibit synthesis of Mycolic acid also suppress the formation of DNA&RNA

Fever,haemotological changes,arthritic, vasculitis, Deficiency of pyridoxine, Haemolytic anaemia,decrease the metabolism of antiepileptics phenytoin,ethosuximide, carbamazapine

2.

Rifampicin

-

Inhibit DNa dependent Rna Polymerase

Skin eruptions,fever,git disturb,inducing of metabolizing enzymes and increase the degradation of warfarin,glucocorticoids, Antidiabetics,narcotic analgesics,dapsone and estrogens failure of oral contraceptives.

ANTI LEPROTIC DRUGS

13

Dapsone

Similar to sulphonamide due to chemical similarity inhibition of paba into folic acid

Inflammatory side effects,heamolysis,metha Moglobinaemia,allergic dermatitis,neuropathy.

14.

Clofazamine

-

Act by interfering with template function of DNA

Skin and urine can developreddish colour,lesions of blue black discolouration,nausea, Giddiness,git disturbs,headache

ANTI VIRAL DRUGS

1

Idoxurudine

virus

Structural analogue of thymidine.Compete with it and gets incorporated into DNA so forms faulty DNA-directs synthesis of wrong viral proteins

2

Ayclovir

Preferentially inhibits viral DNA polymerase when phosporylated by viral thymidine kinases

Local inflammation with iv injection

3

Zidovudine

Preferentially inhibits reverse transcriptase of HIV after conversion into triphosphate by series of kinases.

-

4

Nevirapin& Efavirenz

Directly inhibits HIV Reverse transcriptase without the need of  Phosporylation.

5

Ritonavir

Aspartic protease inhibitor.(protease involved in production of structural protein and enzymes of HIV virus)

6

Amantidine

Blocks viral penetration/uncoating

ANTI MALARIAL DRUGS

1

Chloroquine

Being a weak base gets accumulated in lysosome &raises vesicular PH and interferes with degradation of HB.Also prevents formation of hemozoin by forming chloroquine-heme complex

2

Primaquine

It suppresses the mitochondrial functions of plasmodia in exoerythrocytic stages

ANTI FUNGAL DRUGS

1

Metronidazole

In anaerobic environment its nitro group get reduced into nitro radical which exerts cytotoxicity by damaging DNA & other critical biomolecule

2

Emetin

Inhibit protein synthesis of tropozoites by arresting intrabosmal,translocation and t-RNA  AA complex

3

Amphotericin-B

Binds ergosterol,forms membrane pores that disruptes homeostasis.

4

Ketoconazole

Inhibits funal steroid synthesis

5

Gresiofulvin

Interfers with microtubule function disrupts mitosis

6

Flouroquinalones

Inhibit DNA gyrase (Topoisomerase2)

ANTI CANCER/NEOPLASTIC DRUGS

1.

Alkylating Agents

In neutral /alkaline solutions they form quarternary derivative ethylenium cation-reacts with NH2,SH,OH groups and make them unavailable for metabolic reactions. -since they are nucleophiles reacts with DNA bases and inhibit DNA synthesis

2.

Antimetabolites

1)Folic acid analogues-(Methotrexate)--- S-phase specific antimetabolite folic acid analoguethat inhibits DHF reductase. 2)Pyrimidine AnalogueL: 5-Flouro Uracil