Cephalosporin Pharmacology – Mnemonics

Cephalosporins are one of the most widely prescribed antimicrobial drugs. They can be classified into 5 to generations and the medical students often have hard time remembering the names of drugs falling into different generations as the names appear and sound similar. This is a collection of mnemonics from different sources.

Classification of Cephalosporins

1st Generation		2nd Generation		3rd Generation		4th Generation	5th Generation
Oral	Parenteral	Oral	Parenteral	Oral	Parenteral	Parenteral	Parenteral
Ceph-a-lexin	Cef-a-zolin	Cef-a-clor (exception)	Cefuroxime	Cefixi-me	Cefotaxi-me	Cefi-pi-me	Cefta-ro-line
Cef-a-droxil		Cefuroxi-me axetil (exception)	Cefotetan	Cefpodoxi-me axetil	Ceftizoxi-me	Cefi-pi-rome	Ceftobip-ro-le
Ceph-a-ridine		Loracarbef	Cefoxitin	Ceftibuten	Ceftriaxone	Cef-qui-nome	Cefto-lo-zane
		Cefprozil	Cefmetazole	Cefditoren	Ceftazidi-me
				Cefdinir	Cefoperazone
					Moxalactam

Mnemonic for Oral and Parenteral Cephalosporins

Parenteral:

1. All 4th and 5th generation cephalosporins
2. Have “t” except ceftibuten and cefditoren
3. Having “z” – zone, zolin, zole

Oral: Have “OR” in the name – Cefaclor, Cefditoren, Loracarbef

Menmonic to remember classification by generation of Cephalosporins

A. 5th generation:

• With “ro” and “lo”: ceftobiprole, ceftaroline, ceftolozane

B. 4th generation:

• With “pi” and “qui”: Cefepime, Cefepirome, Cefquinome

C. 1st generation:

All cephalosporins having “A” after “Cef” are 1st generation except Cefaclor.

2 Xs and 1 Z in Dine

• 2 “X” – cefalexin, cefadroxil
• 1 “Z” – cefazolin
• 2 “IN” – cefalothin, cefaparin
• DINE – cephradine

D. 3rd generation:

Cephalosporins ending with “me” are 3rd generation except cefuroxime.

“cef” +/- (a,e,i,o,u) + p/d/t

• cefotaxime, ceftizoxime, ceftriaxone, ceftazidime, cefoperazone
• cefixime, cefpodoxime, cefdinir, ceftibuten, ceftamet

E. 2nd generation:

FURy FOX FOR FON TEA and 2 Ms for a Macho fox

• ceFURoxime, ceFOXitine, ceFORanide, ceFONicid, cefoTEtan
• cefMandole, cefMetazole
• Remember one more drug: Cefaclor

Flomoxef has been classified by different authors into different generations – 2nd, 3rd and 4th generations.

Short review of pharmacology of cephalosporins

A. Class: Beta-lactams (like Penicillin)

B. Mechanism of action: Disrupt cell wall synthesis by inhibiting transpeptidase (cross-linking)

C. Pharmacokinetics:

1. Most are excreted by kideny (tubular secretion).
2. 2 “Zones” are secreted in bile: Ceftriaxone and Cefoperazone

D. Blood brain barrier (BBB) penetration:

1. 1st generation: No BBB penetration
2. 2nd generation: Cefuroxime has highest among 2nd generation
3. 3rd generation: Except Cefoperazone and Cefixime

E. Spectrum of activity:

Generation	Gram Negatives	Gram Positives	β-Lactamase Stability
1st	+	+++	+/-
2nd	++	++	+
3rd	+++	+	++
4th	+++	++	+++
5th	+++	+++	++++

1. 1st generation: Mainly Gram+
   

   Gram – (PEcK): Proteus, E.Coli, Klebsiella

2. 2nd generation: Gram- > Gram+
   

   HEN PEcKS: Haemophilus influenzae, Enterobacter, Neissera, Proteus, E. Coli, Klebsiella, Serratia

3. 3rd generation: Gram – >> Gram +
   

   Ceftriaxone: Meningitis, Gonorrhea
   Ceftazidime and Cefoperazone: Pseudomonas
   Used to treat meningitis and sepsis (can cross Blood Brain Barrier)

4. 4th generation: Pseudomonas
5. 5th generation: MRSA

Activity against Bacteroides:

• 2nd generation: Cefoxitin, Cefotetan and Cefmetazole
• 3rd generation: Ceftizoxime (maximum)

Activity agaisnt pseudomonas:

• Ceftazidime (maximum)
• Ceftazolone
• Cefoperazone

Cephalosporins don’t have activity against: “LAME”

• Listeria
• Atypicals (including Mycoplasma and Chlamydia)
• MRSA (Except 5th generation)
• Enterococci

F. Drug of choice:

1. Surgical prophylaxis: Cefazolin
2. Melioidiosis (Burkholderia psudomalleri): Ceftazidime
3. Gonorrhea, salmonellosis (including typhoid), E. coli sepsis, Proteus, Serratia, Haemophilus and empirical therapy for bacterial
   meningitis: Ceftriaxone
4. Pseudomonal CNS infection: Ceftazidime or Cefepime or Meropenem (For GU and GI infections – Fluoroquinolones and Aminoglycosides)
5. Bacteroides: Metronidazole (Cefoxitin is an alternative along with clindamycin and chloramphenicol)

G. Adverse effects:

1. Drugs with methylthiotetrazole group: Cefamandole, Cefoperazone, Cefotetan, Moxalactam
   • Acts like oral anticoagulant (Vit. K antagonist): Bleeding (hypoporthrombinemia)
   • Disulfiram like reaction
2. Biliary sludging:
   • Ceftriaxone
   • Cefotaxime
3. Taste disutrbance: Ceftobiprole
4. Non-bloody red stools: Cefdinir
5. Nephrotoxicity:
   • Cephaloridine (highest nephrotoxicity)
   • Cephalothin
6. Neutropenia: Ceftazidime
7. Thrombophlebitis (Parenteral)
8. Diarrhea
9. Anaphylaxis

Mnemonic: “DDT HAPeNS”

D – diarrhea
D – disulfiram like reaction
T – thrombophlebitis
H – hypoprothrombinemia
A – allergy (hypersensitivity)
P – pain (severe with i.m.)
N – nephrotoxicity
S – super infections with fungi

H. Summary mnemonics for generation of cephalosporins:

• First Generation = “FA/PHA”
• Second Generation = “Everything Else”
• Third Generation = “ONE/TEN/IME”
• Fourth Generation = “PI” and “QUI”
• Fifth Generation = “ROL”