AMEBIASIS

I. Emetine group : e.g. Emetine, dehydroemetine and its resinate.

II. Quinoline derivatives: Halogenated hyroxyquinolines:

Diiodohydroxyquinoline, iodochloroquine 4 – aminoquinolines: Chloroquine.

III. Imidazole derivatives: Metronidazole, tinidazole, secnidazole, ornidazole

IV. Antibiotics: Tetracyclines, paromomycin.

V. Miscellaneous: Diloxanide furoate and kurchi.

Metronidazole:

Reductive activation by intracellular transport proteins

Reduced by the pyruvate:ferredoxin oxidoreductase system in the mitochondria of obligate anaerobes, which alters its chemical structure.

Reduced intermediate particle interacts with intracellular targets — Cytotoxic intermediate particles interact with host cell DNA, resulting in DNA strand breakage and fatal destabilization of the DNA helix

Metronidazole

• Mechanism of action: – Enters bacteria via cell diffusion– Activated via single reduction step by bacteria

forms radicals reacts with nucleic acid cell death

• Spectrum of activity:– Anaerobic bacteria– Microaerophilic bacteria– Protozoa

• Resistance:– Rare– Mechanism: decreased activation (↓ red ox

reaction) of drug

Metronidazole

• Indications:– Anaerobe infections – C. difficile– H. pylori– Bacterial vaginosis– Trichomonas vaginitis– Amebiasis– Giardiasis

• Drug interactions:– Ethanol– Antacids– CyA/tacrolimus– Lithium– Phenytoin– Rifampin– Warfarin

Metronidazole:

Uses:

1)T vaginalis 2g single dose, 0.7% gel, 500mg – 1g

suppository

2) Amoebiasis

3) Giandaisies

4) Anerobic infections – Bactericides, clostridium,

fusobacterium, peptococcus, peptosirgstococcus,

Eubacterium, H. pyloris.

5) Polymicrobial infections.

6) Prophylaxis of postop mixed bacterial infection

7) Bacterial vaginosis

8) Pseudomembranous colitis

9) Crohns disease with perianal fistulas

Metronidazole•Distribution into tissue•Therapeutic levels:•PMNs•Unobstructed biliary tract•Pancreas•CSF •Empyema fluid•Peritoneal fluid•Hepatic abscess•Pelvic tissues•Vaginal/seminal fluid

•Adverse Effects:–GI: N, V, epigastric distress

–Metallic taste–Darkening of urine–Peripheral neuropathy

–Pancreatitis–Hepatitis–Fever–Reversible neutropenia

IODOQUINOL

EMETINE & DEHYDROEMETINE

PAROMOMYCIN SULFATE

DILOXANIDE FUROATE

Asymptomatic Intestinal Infection

Diloxanide 500 mg tid x 10d

or-

Iodoquinol 650 mg tid x 21d

or-

Paromomyin 10 mg/kg tid x 7d

Mild to Moderate Intestinal Infection

Metronidazole 750mg tid x 10d

or-

Tinidazole 2g od x 3d

Plus-

Luminal agent

Mild to Moderate Intestinal Infection

Alternative: Luminal agent

Plus either-

Tetracycline 250mg tid x 10d

or-

Erythromycin 500 mg qid x 10d

Severe Intestinal Infection

Metronidazole 750mg tid (500mg IV every 6 h)

or

Tinidazole plus

Luminal agent

Alternative:

Luminal agent plus either

Tetracycline or

Dehydroemetine 1mg /kg SC/IM x 3-5d

Hepatic / Extra intestinal

Same as above

Alternative:

Dehydroemetine 1mg /kg S.C/IM x 3-5d

Followed by (liver abscess only) Chloroquine 500mg bd x 2d, then 500mg od x21d

Plus

Luminal agent

PENTAMIDINE:

Pnenmocytosis sleeping sickness leishmaniasis

Parenteral

omebahized powder,

LEISHMANIASIS:-

1) Liposonal anyrhotencin

2) Pentroalent antimonish. Sodium

stibozhconate meglumine antimonite

3) Miltefosine

4) Pent amidine isethionate

5) paromorycin

CUTANEOUS:

1) Pentacalant antimoniab

2) As above

3)Antifungals, allopunol

TOPICAL:

1) Iutratesional antimony

2) Paromomycin oint

3) Cryotherapy

4) local heat

5) surgical removal

SODIUM STIBOGLUCONATE:-

IV / IM.

Iutial t1/ 2 – 2 h

Terminal t1/ 2 – 24 h

20 mg / kg 1d x 20 d

ADR:

G.I headache, arthralgia, rash

- IM – Stenile abscers

- ECG

- Hemolytic anemia

- LFT, renal effects,

NITAZOXANIDE:

General. Lanbia C. Parvum

E. histohytica A. Iumbricoides

Several tapumorns

Increase Tizoxamide

MILTEFOSINE:-

- 2.5mg / kg / d x 28 d

- Single dose amp B + 7 – 14 d miltepoine

- G. I.

- Decrease LFT

- Not in Pregnancy

- Resistance is a problem. Combination

PAROMOMYCIN:-

11mg / kg x 21 d IM

- ADR as with AGI