sulfonamides
DESCRIPTION
SULFONAMIDES. First effective chemotherapeutic agent. Chemistry. Structural analogue of PABA . Sulfonamides are with diff. chemical, physical, pharmacological and anti bacterial properties. - PowerPoint PPT PresentationTRANSCRIPT
SULFONAMIDESSULFONAMIDES
First effective chemotherapeutic First effective chemotherapeutic agentagent
ChemistryChemistry
Structural analogue of Structural analogue of PABAPABA.. Sulfonamides are with diff. chemical, physical, Sulfonamides are with diff. chemical, physical,
pharmacological and anti bacterial properties. pharmacological and anti bacterial properties. Produced by substitutions at gp (-SOProduced by substitutions at gp (-SO22 –NH –R) –NH –R)
or the amide group (-NH2) of sulfanilamide or the amide group (-NH2) of sulfanilamide nucleus. nucleus.
Sulfanilamide is Sulfanilamide is para-aminobenzenesulfonamidepara-aminobenzenesulfonamide
CLASSIFICATIONCLASSIFICATIONI.I. Well absorbed by Mouth and Rapidly eliminated Well absorbed by Mouth and Rapidly eliminated
(short Acting)(short Acting)
a.a. General PurposeGeneral Purpose SulfadiazineSulfadiazine
b.b. Mainly for UTIMainly for UTI SulfisoxazoleSulfisoxazole SulphamethizoleSulphamethizole SulfamethoxazoleSulfamethoxazole
II.II. Well absorbed by GIT and Slowly eliminated (Long Well absorbed by GIT and Slowly eliminated (Long Acting)Acting)
SulphadoxineSulphadoxine SulphamethoxypyridazineSulphamethoxypyridazine Sulphadimethoxine Sulphadimethoxine Sulphaphenazole Sulphaphenazole
III.III. Poorly absorbed by GITPoorly absorbed by GIT Sulfasalazine Sulfasalazine
IV.IV. For Topical ApplicationFor Topical Application SulfacetamideSulfacetamide Silver SulfadiazineSilver Sulfadiazine Mafenide Mafenide
V.V. Miscellaneous GroupMiscellaneous Group
SulfapyridineSulfapyridine
VI.VI. Sulfonamide CombinationSulfonamide Combination CotrimoxazoleCotrimoxazole (Sulfamethoxazole & trimethoprim) (Sulfamethoxazole & trimethoprim) FansidarFansidar (Sulfadoxine & Pyrimethamine) (Sulfadoxine & Pyrimethamine)
Mostly well absorbed after oral adm. Divided into three major Mostly well absorbed after oral adm. Divided into three major
groups.groups.
1.1. Oral absorbable Oral absorbable
2.2. Oral non absorbable Oral non absorbable
3.3. Topical Topical
PHARMACOKINETICSPHARMACOKINETICS
Oral absorbableOral absorbable
absorption – stomach and intestine absorption – stomach and intestine Distribution – Widely distributed Distribution – Widely distributed
CNS, CSF, placenta and fetusCNS, CSF, placenta and fetusPPB 20 – 90 % to serum albumin PPB 20 – 90 % to serum albumin PPL 2 – 6 hrs PPL 2 – 6 hrs Metabolism – Liver Metabolism – Liver Excretion – Urine , feces, bile, milk and other Excretion – Urine , feces, bile, milk and other secretionssecretions
MetabolismMetabolism
A portion of the absorbed drug is acetylated or A portion of the absorbed drug is acetylated or glucronidated in the liver.glucronidated in the liver.
Dosage reduction is required in renal failure.Dosage reduction is required in renal failure.
MOAMOAThey are bacteriostatic They are bacteriostatic
PABA
Dihydrofolic Acid (Folate)
Tetrahydrofolic Acid
Purines
DNA
Dihydropteroate Synthase
Dihydrofolate Reductase
SulfonamidesX
X Trimethoprim
Sulfonamides susceptible organisms, unlike Sulfonamides susceptible organisms, unlike mammals, cannot use exogenous folate but mammals, cannot use exogenous folate but must synthesize it from PABA. must synthesize it from PABA.
ANTIBACTERIAL SPECTRUM ANTIBACTERIAL SPECTRUM
Exert bacteriostatic effectExert bacteriostatic effect Gram +ve and Gram -ve bacteriaGram +ve and Gram -ve bacteria Some enteric bacteria like Some enteric bacteria like
E. Coli, Shigella, Salmonella, Klebsiella.E. Coli, Shigella, Salmonella, Klebsiella. Nocardia, Chlamydia trachomatis and some Nocardia, Chlamydia trachomatis and some
protozoa.protozoa.
ResistanceResistance
Mammalian cells lack the enzymes required Mammalian cells lack the enzymes required for folate synthesis from PABA and depend on for folate synthesis from PABA and depend on exogenous source of folate, so they are not exogenous source of folate, so they are not susceptible to sulfonamides.susceptible to sulfonamides.
Resistance in bacteriaResistance in bacteria Sulfonamides resistance may occur as a result of Sulfonamides resistance may occur as a result of
mutations.mutations. A- Overproduction of PABAA- Overproduction of PABA B- Production of a folic acid synthesizing B- Production of a folic acid synthesizing
enzyme that has low affinity for sulfonamides.enzyme that has low affinity for sulfonamides. C- Impair permeability to the sulfonamide or C- Impair permeability to the sulfonamide or
active effluxactive efflux An alternative metabolic pathway for synthesis An alternative metabolic pathway for synthesis
of essential metaboliteof essential metabolite
Therapeutic UsesTherapeutic Uses
A- Oral Absorbable AgentsA- Oral Absorbable Agents
Urinary Tract InfectionsUrinary Tract Infections
Not therapy of first choiceNot therapy of first choice
Sulfadiazine with pyrimeythamine---acute Sulfadiazine with pyrimeythamine---acute toxoplasmosistoxoplasmosis
B- Oral Nonabsorbable AgentsB- Oral Nonabsorbable Agents
Sulfasalazine is used in ulcerative collitis, Sulfasalazine is used in ulcerative collitis, enteritis and other inflammatory bowl disease.enteritis and other inflammatory bowl disease.
C- Topical AgentsC- Topical Agents
Sodium sulfacetamide ophthalmic Sodium sulfacetamide ophthalmic solution or ointment is used for solution or ointment is used for
Bacterial conjunctivitisBacterial conjunctivitis
TrachomaTrachoma
Silver sulfadiazine used for prevention of Silver sulfadiazine used for prevention of infection of burn wounds.infection of burn wounds.
Nocardiosis:Nocardiosis:
Sulfisoxazole or sulfadiazineSulfisoxazole or sulfadiazine
Used in combination Used in combination • Pneumocystis Carinii – sulfamethoxazole Pneumocystis Carinii – sulfamethoxazole
combined with trimethoprim (Co-trimoxazole)combined with trimethoprim (Co-trimoxazole)
• Resistant Malaria (Sulfadoxine + Resistant Malaria (Sulfadoxine + Pyrimethamine – Fansidar)Pyrimethamine – Fansidar)
• Acute toxoplasmosis – (Sulfadiazine + Acute toxoplasmosis – (Sulfadiazine + Pyrimethamine)Pyrimethamine)
ADVERSE EFFECTSADVERSE EFFECTS
A.A. Hypersensitivity Reactions:- Hypersensitivity Reactions:-
1. Fever, Skin rashes, exfoliative dermatitis, photosensitivity, 1. Fever, Skin rashes, exfoliative dermatitis, photosensitivity,
urticaria, N, V, D Angioedema & Steven – Johnson syndromeurticaria, N, V, D Angioedema & Steven – Johnson syndrome
Stomatitis, conjunctivitis, arthritis and hepatitis. Stomatitis, conjunctivitis, arthritis and hepatitis.
2.Hematopoietic Disturbances :- Hemolytic or Aplastic anemia, 2.Hematopoietic Disturbances :- Hemolytic or Aplastic anemia,
Granulocytopenia, Thrombocytopenia, Leukemoid reactionsGranulocytopenia, Thrombocytopenia, Leukemoid reactions
Can provoke hemolytic reactions in patients Can provoke hemolytic reactions in patients with glucose-6-with glucose-6-
phosphate dehydrogenase deficiency.phosphate dehydrogenase deficiency.
Urinary Tract DisturbancesUrinary Tract Disturbances:- Sulfonamides :- Sulfonamides may precipitate in urine, especially at neutral may precipitate in urine, especially at neutral or acid pH producing crystalluria, Hematuria or acid pH producing crystalluria, Hematuria or even obstruction and nephritisor even obstruction and nephritis
Less with sulfisoxazole.Less with sulfisoxazole. Treatment Treatment
Sodium bicarbonate and adequate Sodium bicarbonate and adequate hydration.hydration.
CONTRAINDICATIONSCONTRAINDICATIONS
Premature babies, newborns & infants less Premature babies, newborns & infants less than 2 monthsthan 2 months
Pregnant woman at term – KernicterusPregnant woman at term – Kernicterus Displacement of bilirubin from plasma Displacement of bilirubin from plasma
albumin. albumin. Deposition of bilirubin in basal ganglia and Deposition of bilirubin in basal ganglia and
sub thalamic nuclei of brain.sub thalamic nuclei of brain.
Drug interactionsDrug interactions
Oral anticoagulantsOral anticoagulants Sulfonylurea Sulfonylurea Hydantoin anticonvulsantsHydantoin anticonvulsants Potentiate the effect of these drugsPotentiate the effect of these drugs Inhibition of metabolism or displacement from Inhibition of metabolism or displacement from
albuminalbumin
TRIMETHOPRIMTRIMETHOPRIM
ChemistryChemistry::
Trimethoxybenzyl PyrimidineTrimethoxybenzyl Pyrimidine
Chemically Related to anti malarial drug pyrimethamine Chemically Related to anti malarial drug pyrimethamine
both are folate antagonists. both are folate antagonists.
PABA
Dihydrofolic Acid (Folate)
Tetrahydrofolic Acid
Purines
DNA
Dihydropteroate Synthetase
Dihydrofolate Reductase
SulfonamidesX
X Trimethoprim
MOAMOA
PharmacokineticsPharmacokinetics
Given orally fully absorbed from GIT.Given orally fully absorbed from GIT.
Distribution:- Widely distributed, in body fluids and Distribution:- Widely distributed, in body fluids and
tissues, including CSF concentrates in acidic media of tissues, including CSF concentrates in acidic media of
prostatic and vaginal fluid.prostatic and vaginal fluid.
PPB: 65 – 70 %PPB: 65 – 70 %
Excretion : in urine within 24 hrs.Excretion : in urine within 24 hrs.
ResistanceResistance
Reduced cell permeability.Reduced cell permeability. Overproduction of dihydrofolate reductase.Overproduction of dihydrofolate reductase. Production of altered reductase with reduced Production of altered reductase with reduced
drug binding.drug binding.
Resistance is plasmid encoded.Resistance is plasmid encoded.
Clinical UsesClinical Uses Acute UTI: 100 mg – B.d.Acute UTI: 100 mg – B.d. Bacterial Prostatitis (Fluroquinolones are Bacterial Prostatitis (Fluroquinolones are
preferred )preferred )
CO-TRIMOXAZOLECO-TRIMOXAZOLE
Combination of trimethoprim with Combination of trimethoprim with
sulfamethoxazole.sulfamethoxazole.
Sulfamethoxazole – 400 mg. Ratio 1:5Sulfamethoxazole – 400 mg. Ratio 1:5
Trimethoprim – 80 mg.Trimethoprim – 80 mg.
One double strength tablet trimethoprim 160 One double strength tablet trimethoprim 160
mgmg
Sulfamethoxazole 800 mg Sulfamethoxazole 800 mg
Advantages of Using Co-TrimoxazoleAdvantages of Using Co-Trimoxazole
1.1.Bactericidal. (Individual drugs are bacteriostatic) Bactericidal. (Individual drugs are bacteriostatic)
2.2.Wide antibacterial spectrum.Wide antibacterial spectrum.
3.3.More efficacy.More efficacy.
4.4.Less dose of each drug.Less dose of each drug.
5.5.Less incidence of toxicity.Less incidence of toxicity.
PHARMACOKINETICSPHARMACOKINETICS
Can be given orally or I/VCan be given orally or I/V
MOAMOAPABA
Dihydrofolic Acid (Folate)
Tetrahydrofolic Acid
Purines
DNA
Dihydropteroate Synthetase
Dihydrofolate Reductase
SulfonamidesX
X Trimethoprim
Antibacterial spectrumAntibacterial spectrum
Gram +ve and gram –ve organisms (resistant Gram +ve and gram –ve organisms (resistant to individual drugs)to individual drugs)
Chlamydia diphtheriaeChlamydia diphtheriae and and N meningitidisN meningitidis.. E. coli, Proteus mirabilis, Proteus marginii, E. coli, Proteus mirabilis, Proteus marginii,
Enterobacter spp, Salmonella, Shigella, Enterobacter spp, Salmonella, Shigella, PseudomonasPseudomonas and and SerratiaSerratia are inhibited. are inhibited.
Klebsiella, Brucella, Pasteuralia, Yersinia Klebsiella, Brucella, Pasteuralia, Yersinia andand Nocardia asteroids.Nocardia asteroids.
Bacterial ResistanceBacterial Resistance
Plasmid mediated that codes for an altered Plasmid mediated that codes for an altered dihydrofolate reductase.dihydrofolate reductase.
Pharmacokinetics Pharmacokinetics
Pharmacokinetic profiles of sulfamethoxazole Pharmacokinetic profiles of sulfamethoxazole and trimethoprim are closely matched to and trimethoprim are closely matched to achieve a constant ratio of 20: 1 in their achieve a constant ratio of 20: 1 in their concentrations in blood and tissues.concentrations in blood and tissues.
Readily enters CSF and sputum.Readily enters CSF and sputum. Excreted through kidneys.Excreted through kidneys.
1.1. Respiratory infections:Respiratory infections:Pneumocystis jiroveci Pneumocystis jiroveci Pneumonia in AIDS patientPneumonia in AIDS patientHemophilis influenzae Hemophilis influenzae Streptococcus pneumoniae Streptococcus pneumoniae Moraxella catarrhalis Moraxella catarrhalis Klebsiella pneumoniaeKlebsiella pneumoniaeI/V use is for moderate to severe pneumocystis I/V use is for moderate to severe pneumocystis
pneumonia, gram-negative bacterial sepsis pneumonia, gram-negative bacterial sepsis Caused by multidrug-resistant species.Caused by multidrug-resistant species.
CLINICAL USESCLINICAL USES
Acute otitis media in childrenAcute otitis media in children Acute maxillary sinusitis in adults.Acute maxillary sinusitis in adults.
2.2. GIT Infections:GIT Infections:ShigellosisShigellosisSystemic Systemic SalmonellaSalmonella infection (Typhoid Fever) infection (Typhoid Fever)
3. UTI uncomplicated, complicated and recurrent.3. UTI uncomplicated, complicated and recurrent.4. Prostatitis 4. Prostatitis 5. Acute Gonococcal Urethritis 5. Acute Gonococcal Urethritis 6. Non tuberculous mycobacterial infections 6. Non tuberculous mycobacterial infections
Prophylaxis in Neutropenic patientsProphylaxis in Neutropenic patients
Low dose therapy Low dose therapy
Emergence of resistant bacteria limit its Emergence of resistant bacteria limit its use.use.
Useful in carriers of Useful in carriers of Salmonella typhi Salmonella typhi
Adverse effectsAdverse effects
Folate deficient cells Folate deficient cells Megaloblastic anemia Megaloblastic anemia Leukopenia Leukopenia ThrombocytopeniaThrombocytopenia 75% of untoward effects involve skin 75% of untoward effects involve skin Nausea, vomiting, drug fever, vasculitis, renal Nausea, vomiting, drug fever, vasculitis, renal
damage, CNS disturbances.damage, CNS disturbances.
Pyrimethamine and sulfonamidePyrimethamine and sulfonamide
Pyrimethamine + sulfadiazine used for Pyrimethamine + sulfadiazine used for treatment of leishmaniasis and toxoplasmosis.treatment of leishmaniasis and toxoplasmosis.
Pyrimethamine + sulfadoxine used for Pyrimethamine + sulfadoxine used for Falciparum malaria. Falciparum malaria.
Adverse EffectsAdverse Effects
1.1. Hematological Hematological
Trimethoprim – Megaloblastic Anemia, Leukopenia, Trimethoprim – Megaloblastic Anemia, Leukopenia,
Granulocytopenia Granulocytopenia
Prevented by simultaneous administrations of folinic acid Prevented by simultaneous administrations of folinic acid
6 – 8 mg/D which does not enter bacteria.6 – 8 mg/D which does not enter bacteria.
2.2. Rashes, Fever, Vasculitis Rashes, Fever, Vasculitis
2.2. GIT dist. – Nausea, vomiting, Glossitis & GIT dist. – Nausea, vomiting, Glossitis &
stomatitis.stomatitis.
3.3. HIV patients with pneumocystis pneumonia HIV patients with pneumocystis pneumonia
shows fever, rashes, leukopenia, diarrhea, shows fever, rashes, leukopenia, diarrhea,
elevation of hepatic aminotransferases, elevation of hepatic aminotransferases,
hyperkalemia, hypernatremia. hyperkalemia, hypernatremia.
That’s all for todayThat’s all for today