All Top 100 Drugs- 2025

Includes classes, generic and brand names, indications, formulations, MOAs, adverse effects, contraindications, boxed warnings, and counseling

Classes of Antibiotics

Penicillin (PCN), Cephalosporin, Fluoroquinolone (FQ), Macrolide, Tetracycline, Sulfonamide

Penicillin Common Medications

Amoxicillin and Amoxicillin-clavulanate

Cephalosporin Common Medications

Cephalexin and Cefdinir

Fluoroquinolone Common Medications

Ciprofloxacin and Levofloxacin

Macrolide Common Medications

Azithromycin

Tetracycline Common Medication

Doxycycline

Sulfonamide Common Medications

Sulfamethoxazole-trimethoprim

Amoxicillin Formulations

Capsules, tablets, chewable tablets, powder for suspension (Amoxil), and ER tablet

Amoxicillin Indications

Otitis media, prophylaxis for endocarditis, pharyngitis

Amoxicillin and Cephalosporin Mechanism of Action

Beta-lactam- inhibits bacterial cell wall synthesis by binding to penicillin binding proteins

Penicillin Common Adverse Effects

Nausea/vomiting/diarrhea, rash, headache, yeast infections

Amoxicillin Serious Adverse Effects

Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), Clostridium difficile diarrhea

Penicillin Contraindications

Serious hypersensitivity reactions such as SJS or anaphylaxis to previous beta-lactams

Amoxicillin-clavulanate Formulations

Tablets, chewable tablets, powder for suspension (Augmentin), and ER tablet

Amoxicillin-clavulanate Indications

Otitis media, sinusitis, pneumonia

Amoxicillin-clavulanate Mechanism of Action

Amoxicillin: beta-lactam- inhibits bacterial cell wall synthesis by binding to penicillin binding proteins

Clavulanate (or clavulanic acid): beta-lactamase inhibitor

Amoxicillin-clavulanate Serious Adverse Effects

Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), Clostridium difficile diarrhea, increased liver function tests (LFTs), hepatotoxicity

Penicillin Counseling

Finish all. Store solutions/ suspensions appropriately. Stop taking and alert pharmacy and prescriber if reaction develops. May cause N/V/D or rash. Report severe diarrhea. Take Amoxicillin-clavulanate with food.

Cephalexin (1st generation) Formulations

Capsules, tablets, powder for suspension (Keflex)

Cephalexin (1st generation) Indications

Otitis media, pharyngitis, respiratory tract infections, urinary tract infections, impetigo

Cephalexin (1st generation) Common Adverse Effects

Diarrhea

Cephalexin (1st generation) Serious Adverse Effects

Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), anaphylaxis

Cephalosporins Contraindications

Serious hypersensitivity reactions such as SJS or anaphylaxis to previous cephalosporins

Cefdinir (3rd Generation) Formulations

Capsules and powder for suspensionn (Omnicef)

Cefdinir (3rd Generation) Indications

Otitis media, bronchitis, pneumonia, pharyngitis, sinusitis

Cefdinir (3rd Generation) Common Adverse Effects

N/V/D, yeast infections

Cefdinir (3rd Generation) Serious Adverse Effects

SJS, TEN, erythema multiforme, anaphylaxis, serum sickness

Cephalosporin Counseling

Finish all. Store suspensions appropriately. Stop taking and alert pharmacy and prescriber if reaction develops. May cause N/V/D or rash. Report severe diarrhea. Potential cross-sensitivity in penicillin allergic patients.

Cefinir specific: Take with food. Suspension may cause stool to turn red. Report severe rash, urticaria, fever, malaise. Separate at least 2 hours from calsium-, aluminum-, magnesium-, or iron-containing products

Ciprofloxacin Formulations

Tablets, powder for oral suspension, injectable solution (Cipro), ER tablets, ophthalmic ointment and solution, otic solution

Levofloxacin Formulations

Tablets, oral solutionm, injectable solution (Levaquin), ophthalmic solution

Fluoroquinolone Indications

Pneumonia (levofloxacin), urinary tract infections

Fluoroquinolone Mechanism of Action

Inhibit bacterical DNA topoisomerase IV and DNA gyrase → prevents supercoiling of DNA resulting in DNA breakage

Fluoroquinolone Common Adverse Effects

N/V/D, headache, rash

Fluoroquinolone Serious Adverse Effects

QT prolongation (heart beat), photosensitivity, SJS, TEN, Clostridium difficile diarrhea, glucose disturbances, seizures, hepatotoxicity, renal failure, bone growth suppression in children

Fluoroquinolone Boxed Warnings

Tendon inflammation and/or rupture, possible exacerbation of muscle weakness related to myasthenia gravis, reserve use for patients with no alternative treatment options for uncomplicated UTI and acute bacterial exacerbation of chronic bronchitis or acute bacterial sinusitis

Ciprofloxacin Contraindications

Concurrent use with tizanidine, hypersensitivity to quinolones

Fluoroquinolone Counseling

Finish all. Store solutions/suspensions appropriately. Stop taking and alert pharmacy and prescriber if reaction develops. May cause N/V/D or rash. Report severe diarrhea. May cause increased sun sensitivity. Report tendon pain or tenderness. Check blood glucose regularly for patients with diabetes. Separate at least 2 hours from Ca-, Al-, Mg-, or Fe-containing products. Drink water to maintain adequate hydration.

Azithromycin Formulations

Tablets (Zithromax), powder for oral suspension(Zithromax), injectable solution (Zithromax), powder for ER suspension, ophthalmic solution

Azithromycin Indications

Pneumonia, COPD exacerbations, pharyngitis, sexually transmitted infections, otitis media

Azithromycin Mechanism of Action

Binds to 50S ribosomal subunit → inhibition of bacterial protein synthesis

Azithromycin Common Adverse Effects

N/V/D, abdominal pain, flatulence, headache, abnormal vision

Azithromycin Serious Adverse Effects

QT prolongation, SJS, TEN, Clostridium difficile diarrhea, hepatotoxicity

Azithromycin Contraindications

History of cholestatic jaundice/hepatic dysfunction with prior use and prior hypersensitivity with macrolide use.

Macrolide Counseling

Finish all. Store solutions/suspensions appropriately. Stop taking and alert pharmacy and prescriber if reaction develops. May cause N/V/D or rash. Report severe diarrhea. Take on empty stomach. Separate at least 2 hours from calcium-, aluminum-, magnesium-, or iron-containing products.

Doxycycline Formulations

Hyclate salt: capsules (Vibramycin), tablets, delayed-release capsules, sprinkle capsules, powder for injectable solution

Monohydrate salt: capsules (Monodox), biphasic release capsules, tablets, powder for oral suspension

Doxycycline Indications

Pneumonia, tick-borne illness, MRSA skin infections, acne, malaria prophylaxis

Doxycycline Mechanism of Actions

Binds reversibily to 30S ribosomal subunit → unhibition of bacterial protein synthesis

Doxycycline Common Adverse Effects

N/V/D, photosensitivity

Doxycycline Serious Adverse Effects

SJS, TEN, Clostridium difficile diarrhea, hepatotoxicity, bone growth suppression and teeth discoloration in children

Doxycycline Contraindications

Previous hypersensitivity with tetracyclines

Tetracycline Counseling

Finish all. Store solutions/suspensions appropriately. Stop taking and alert pharmacy and prescriber if reaction develops. May cause N/V/D or rash. Report severe diarrhea. Separate at least 2 hours from calcium-, aluminum-, magnesium-, or iron-containing products. May cause increased sun sensitivity. Risk of bone growth suppression and teeth discoloration in children. Take with 8 ounces of water. Do not lie down immediately after taking medication.

Sulfamethoxazole-trimethoprim Formulations

Tablets (Bactrim, Septra) and oral suspension (Septra, Sulfatrim)

Sultamethoxazole-trimethoprim Indications

Urinary tract infections, skin and soft tissue infections

Sultamethoxazole-trimethoprim Mechanism of Action

Sulfamethoxazole: interferes with bacterial folic acid synthesis by inhibiting dihydrofolic acid formation from para-aminobenzoic acid

Trimethoprim: inhibits dihydrofolic acid reduction to tetrahydrofolate → inhibition of enzymes of the folic acid pathway

Sultamethoxazole-trimethoprim Common Adverse Effects

N/V/D, rash, urticaria, loss of appetite

Sultamethoxazole-trimethoprim Serious Adverse Effects

Crystalluria, photosensitivity, SJS, TEN, C. diff. diarrhea, blood dyscrasias including agranulocytosis and aplastic anemia

Sultamethoxazole-trimethoprim Contraindications

Hypersensitivity to either component, age <2 months, pregnancy, breastfeeding, anemia due to folate defiency, renal or hepatic disease.

Sulfonamide Counseling

Finish all. Store suspension appropriately. Stop taking and alert pharmacy and prescriber if reaction develops. May cause N/V/D or rash. Report sever diarrhea. May cause increased sun sensitivity. Drink water to maintain hydration.

Lincosamide Common Medication

Clindamycin

Clindamycin Formulations

Capsules, solution for injection (Cleocin), granules for oral solution, topical pledget (wipe), topical gel, topical lotion, topical solution, topical foam, vaginal cream, vaginal suppositories

Clindamycin Indications

Oral for skin infections and abdomical infections, topical for bacterial vaginosis or acne, prevention of infections during dental procedures

Clindamycin Mechanism of Action

Reversibly binds 50S ribosomal subunit → inhibits bacterial protein synthesis

Clindamycin Common Adverse Effects

N/V/D, abdominal pain, rash

Clindamycin Serious Adverse Effects

Clostridium difficile colitis, increased liver function tests, erythema multiforme, SJS, TEN, agranulocytosis

Clindamycin Boxed Warnings

Possible severe colitis which might result in fatality

Clindamycin Counseling

Finish all. Store solutions appropriately. Stop taking and alert pharmacy and prescriber if reaction develops. May cause N/V/D or rash. Report severe diarrhea. Take with full glass of water to avoid esophageal irritation.

Topical forms: May cause dryness or skin irritation.

Vaginal forms: May decrease effectiveness of barrier contraceptives. Use another form of birth control for up to 5 days following treatment.

Nitrofuran Common Medication

Nitrofurantoin

Nitrofurantoin Formulations

Capsules (Macrodantin- QID), monohydrate capsules (Macrobid- BID), oral suspension

Nitrofurantoin Indications

Urinary tract infections

Nitrofurantoin Mechanism of Action

Inhibits cell wall synthesis- interferes with bacterial carbohydrate metabolism by inhibition of acetyl-coenzyme A

Nitrofurantoin Common Adverse Effects

N/V/D, loss of appetite, rash, headache, urine discoloration (dark/yellow/orange/brown)

Nitrofurantoin Serious Adverse Effects

Hepatotoxicity, hemolytic anemia, peripheral neuropathy, pulmonary fibrosis

Nitrofurantoin Contraindications

CrCl <60 mL/min, pregnancy at term, hepatic dysfunction with previous use

Nitrofurantoin Counseling

Finish all. Store suspensions appropriately. Stop taking and alert pharmacy and prescriber if reaction develops. May cause N/V/D or rash. Report severe diarrhea. May cause dark or discolored urine. Report breathing difficulty if taking for >6 months. Take with food.

Nitroimidazole Common Medication

Metronidazole

Metronidazole Formulations

tablets and capsules (Flagyl), ER tablets, topical cream, topical gel, topical lotion, vaginal gel, injectable solution

Metronidazole Indications

Bacterial and protozoal infections- bacterial vaginosis, trichomoniasis, giardiasis, amebiasis, and Clostridium difficile infection

Metronidazole Mechanism of Action

Cytotoxic reduced form causes breakage in helical DNA structure → protein breakage and cell death

Metronidazole Common Adverse Effects

N/V/D, abnormal taste, yeast infection vaginitis, headache, dizziness, Jarisch Herxheimer reaction (immune response), rash

Metronidazole Serious Adverse Effects

SJS, TEN, seizures, neuropathies, aseptic meningitis, ototoxicity

Metronidazole Boxed Warnings

Carcinogenic in mice and rats

Metronidazole Contraindications

Use of disulfiram in the past two weeks, use of alcohol-containing products during therapy or within 72 hours of discontinuation, first trimester pregnancy

Metronidazole Counseling

Finish all. Store solutions appropriately. Stop taking and alert pharmacy and prescriber if reaction develops. May cause N/V/D or rash. Report severe diarrhea. May cause metallic taste. Report any abnormal nerve sensations. AVOID ALCOHOL (including mouth wash and cough syrup).

Topical forms: May cause dryness or skin irritation. Avoid contact with eyes.

Vaginal forms: May cause yeast infection. May cause itching and increased menstrual cramping.

Azole Antifungal Common Medication

Fluconazole

Fluconazole Formulations

Tablets, powder for oral suspension, solution for injection (Diflucan)

Fluconazole Indications

Fungal or yeast infections- vaginal yeast infections

Fluconazole Mechanism of Action

Decreases ergosterol synthesis and inhibits cell membrane formation

Fluconazole Serious Adverse Effects

QT prolongation, tosades de pointes, SJS, TEN, agranulocytosis, anaphylaxis, seizures

Fluconazole Contraindications

Concomitant use with drugs metabolized by CYP3A4 that are known to prolong the QT interval (such as erythromycin or quinidine), concomitant use with terfenadine in patients receiving multiple fluconazole doses >4oo mg

Fluconazole Counseling

May cause N/V. Store suspension appropriately. May cause headache. Report any severe rashes. Report any abnormal feelings of heart rate or rhythm.

Guanosine Nucleoside Analog Medication

Acyclovir and valacyclovir

Acyclovir Formulations

Capsules, tablets, oral suspension, solution for injection, topical cream, topical ointment (Zovirax), buccal tablet

Valacyclovir Formulations

Tablets (Valtrex)

Guanosine Nucleoside Analog Indications

Viral infections- herpes zoster (shingles), recurrent herpes simplex labialis, genital herpes simplex

Guanosine Nucleoside Analog Counseling

Oral forms: Drink plenty of water to avoid renal complications. May cause N/V/D. Store suspension appropriately. Elderly patients may experience dizziness, confusion, or somnolence.

Topical forms: May cause burning, itching, or dryness. Only use on external part of lips and face. Use rubber glove with application to avoid transmission.

No form prevents reinfection or transmission of disease.

Guanosine Nucleoside Analog Mechanism of Action

Synthetic purine nucleoside which 1: competitively inhibits viral DNA polymerase, 2: incorporates into and terminates DNA chain, and 3: inactivates viral DNA polymerase

Guanosine Nucleoside Analog Common Adverse Effects

N/V/D, headache, malaise, contact dermatitis (topical)

Guanosine Nucleoside Analog Serious Adverse Effects

Thrombocytopenic purpura/ hemolytic uremic syndrome, neutropenia, increased LFTs, increased SCr

Guanosine Nucleoside Analog Contraindications

Hypersensitivity to milk protein (buccal form)

Neuraminidase Inhibitor Common Medication

Oseltamivir