BEST MNEMONICS

PHARMACOLOGY

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A. GENERAL PRINCIPLES OF PHARMACOLOGY
   1. Pharmacokinetics
   2. Pharmacodynamics
   3. Adverse drug reactions

B. DRUGS ACTING ON AUTONOMIC NERVOUS SYSTEM
   1. Cholinergic and Anticholinergic drugs
   2. Adrenergic and Antiadrenergic drugs

C. DRUGS ACTING ON CENTRAL & PERIPHERAL NERVOUS SYSTEM
   1. Preanaesthetic medications
   2. Skeletal muscle relaxants
   3. Sedatives & hypnotics
   4. Anxiolytics
   5. Antipsychotic drugs
   6. Antidepressant drugs
   7. Mood stabilizers - antimanic drugs
   8. Antiepileptic drugs
   9. Antiparkinsonian drugs
   10. Opioids

D. ANTIINFLAMMATORY DRUGS & IMMUNOSUPPRESSANT DRUGS
   1. Nonsteroidal antiinflammatory drugs (NSAIDs)
   2. Immunosuppressant drugs
   3. Drugs used in Rheumatoid Arthritis & Gout

E. CHEMOTHERAPEUTIC DRUGS
   1. Antibiotics interfering cell wall synthesis
   2. Antibiotics interfering bacterial protein synthesis
   3. Antibiotics interfering bacterial nucleic acids
   4. Antitubercular drugs
   5. Antileprotic drugs
   6. Antifungal drugs
   7. Antiviral drugs
   8. Antimalarial drugs

ANTIMALARIAL DRUGS

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Clinical situation Drug

→Clinical Cure Chloroquine

→Prophylaxis & (Permanent) Primaquine

radical cure Proguanil

Pyrimethamine + a sulphonamide

→Chloroquine resistant/ Quinine

Falciparum malaria Combination of Pyrimethamine + a sulphonamide

(Quinghaosu, Chinese Herb, Halofantrine

Makes Artemisinin Derivatives) Mefloquine

Artesunate,

Artemether (Artemisinin der.)

Doxycycline

ANTIVIRAL DRUGS

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ANTIVIRAL drugs are:

A Acyclovir | in herpes infection except

N Nevirapine & Nelfinavir | Nevirapine & Nelfinavir

T Trifluridine | which are used in HIV

I Idoxuridine | infection

V Vidarabine |

I Indinavir | Protease |

R Ritonavir | inhibitors |

| in HIV

| infection

A AZT or Zidovidine | Reverse transcriptase |

L Lamivudine | inhibitors |

→ Ribavirin is used in Respiratory syncytial virus infection

→Amantadine is used in influenza-A infection

ANTIFUNGAL DRUGS

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→ For topical infections:

Candidiasis & Ring worm:

Clotrimazole & Related drugs e.g. Miconazole, Itraconazole, Ketoconazole, Fluconazole,etc.

→ For systemic infections:

Aspergillosis, Blastomycosis, Coccidiodomycosis & Cryptococcosis:

Amphotericin-B (deoxy) Cholate Complex I.V. is the drug of choice.

ANTILEPROTIC DRUGS

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Most important side-effect of antileprotic drugs (C,D,E)

1. Clofazimine: Cutaneous discoloration e.g. on cheeks is cosmetically unacceptable

2. Dapsone: Degradation of RBCs (due to methemoglobinemia)

Ethionamide: Emesis

ANTITUBERCULAR DRUGS

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FIRST line drugs:[HRZSE]

F Field defects causing drug i.e. Ethambutol [E]

I Isoniazid (INH) [H]

R Rifampicin [R]

S Streptomycin [S]

T Twice a day given drug i.e. Pyrazinamide [Z]

(All other first line antituberculars are given once a day)

SECOND line drugs:

S Salicylates like Para-amino salicylate

E Ethionamide

C Cycloserine

O Old drug: Thiacetazone

N Newer Drugs:

Quinolones e.g. Ciprofloxacin, Ofloxacin

Macrolides e.g. Clarithromycin, Azithromycin

D Drugs rarely used:

Aminoglycosides e.g. Capreomycin, Kanamycin, Amikacin

Adverse effects of first line anti-tubercular drugs:

1. INH: Insanity (i.e. psychosis), optic [for eye(I)]Neuritis, Hepatitis

2. Rifampicin: Red discoloration of urine, induction of liver enzymes and its toxicity, flu like symptoms

3. Pyrazinamide: Pain in the joints which may also be gout due to hyperuricemia (Plus hepatotoxicity)

4. Ethambutol: Eye toxicity – field defects, loss of visual acquity & colour vision

Streptomycin: Similar to all aminoglycosides i.e. nephro-neuro-oto-toxicity

ANTIBACTERIALS INTERFERING BACTERIAL NUCLEIC ACIDS

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Sulfonamides (SULFA drugs)

S Steven-Johnson syndrome/ Skin rash/ Solubility low

U Urine precipitation/ Useful for UTI

L Large spectrum (gram +ve as well as gram –ve)

F Folic acid synthesis blocker

A Analog of PABA

Drugs used in typhoid or enteric fever (‘C’s):

1. Ciprofloxacin: DOC in adults

2. Cephalosporins*: DOC in children

3. Chloramphenicol#

4. Co-trimoxazole#

# Resistrance has developed

* Cephalosporins of third generation are used

e.g. Cef-triaxone, Cefo-taxime, Cef-tazidime

ANTIBIOTICS INTERFERING BACTERIAL PROTEIN SYNTHESIS

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AMINOGLYCOSIDES:

A Active against all aerobic gram –ve bacilli

M Mechanism: Misreading of mRNA codon, interfering the bacterial protein synthesis

I Ionize completely in solution (hydrophilic). So do not cross biological membranes,

therefore not absorbed orally, remain in ECF & excreted unchanged in urine

N Nephro-Neuro-toxic; so have a Narrow margin of safety

O Oto-toxic i.e. vestibular damage causing vertigo & cochlear damage causing

deafness and tinnitus

G Gentamicin is the prototype. Other aminoglycosides are:

Streptomycin, Amikacin, Netilmicin, Neomycin,etc.

MACROLIDES:

M Main agent i.e. prototype drug used since 1950 is Erythromycin

Newer analogues are:

A Azithromycin

C Clarithromycin

R Roxithromycin

Clinical uses of macrolides:

(Remember vaccines of national immunization programme

e.g. DPT, Measles, Polio & BCG)

D Diphtheria

P Pertusis (=whooping cough)

T Tetanus

M Mycoplasma and legionaire’s pneumonia

P Penicillin alternative in penicillin allergic patients

B Bacterial diarrhoeas as caused by Campylobacter jejuni

C Chancroid caused by H. ducreyi

G Genital infections caused by Chlamydia

ANTIBIOTICS INTERFERING CELL WALL SYNTHESIS

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Penicillins

Penicillins are one of the safest antibiotics.

However, they have the following A.D.R.’s:

A Allergic reactions e.g. Angioneurotic oedema & Anaphylactic shock

D Diarrhoea due to opportunistic infections

R Rare toxicities with Raised plasma penicillin concentrations

e.g. acute high doses causes convulsions &

chronic administration may cause anemia & neutropenia

DRUGS USED IN RHEUMATOID ARTHRITIS & GOUT

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DRUGS USED IN RHEUMATOID ARTHRITIS(RA)

Indications of Auranofin, Aurothioglucose and Aurothiomalate:

(Aurum is the latin for “gold” as these are all gold compounds)

Acts upon rheumatoid

These gold compounds are the most effective agents to arrest the rheumatoid process and are called Disease Modifying Anti-Rheumatoid Drugs (DMARDs). Its alternatives are d-Penicillamine, Choloroquine, Sulfasalazine, Leflunomide and Immunosuppresants. On the other hand NSAIDs are given to afford symptomatic pain relief in RA.

DRUGS USED IN GOUT

1. Suppressing Acute Attacks:

Specific drug i.e. Colchicine

Antiinflammatory nonsteroidal e.g. Indomethacin

Antiinflammatory steroidal e.g. Prednisolone

2. Preventing Attacks:

Probenecid (promote uric acid excretion)

Allopurinol (decrease uric acid synthesis)

IMMUNOSUPPRESSANT DRUGS

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Immunosuppresant drugs are (‘C’s):

1. Cytokine release inhibitors:

· Corticosteroids e.g. Prednisolone

· Cyclosporine, Tacrolimus

2. Cidal drugs against lymphocytes:

· Cytotoxic drugs e.g. Cyclophosphamide, Azathioprine

CD₃ monoclonal antibody, Rh₀ (D) antibodies

NONSTEROIDAL ANTIINFLAMMATORY DRUGS

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N.S.A.I.D.s are classified as:

N Negligible anti-inflammatory but good analgesics:

Paracetomal (=Acetaminophen), Metamizol, Propiphenazone

(All others are good anti-inflammatory & analgesic)

S Salicylates: Acetyl salicylic acid (Aspirin) & Sodium salicylate

A Acid derivatives: (other than salicylates)

· Propionic acid derivatives

e.g. Ibuprofen, Ketoprofen, & Naproxen

· Anthranilic acid derivatives

e.g. Mephenamic acid

· Aryl-acetic acid derivatives

e.g. Diclofenac & Tolmetin

I Indoles: Indomethacin & Sulindac

D Drugs with long duration of action:

· Pyrazolones e.g. Phenylbutazone, Oxyphenbutazone

· Oxicams e.g. Piroxicam, Tenoxicam

S Selective COX-2 inhibitors:

· Relatively selective

e.g. Nimesulide, Nabumetone & Meloxicam

· Highly selective

e.g. Celecoxib, Rofecoxib, Valdecoxib, Etoricoxib

OPIOIDS

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Clinical uses:

A As analgesic & Acute Left Ventricular Failure

B Balanced anaesthesia (incl. Preanaesthetic medication and Neurolept analgesia)

C Cough

D Diarrhoea

Adverse effects:

A Apnoea & Allergy

B B.P. fall & Blurring of vision

C Constipation & Chronic use leading to tolerance and dependence

D Dysphoria & Dysuria

ANTIPARKINSONIAN DRUGS

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PARKINSONISM

Clinical presentation:

P Paucity of movements (bradykinesia)

A Abnormal movements (coarse tremors) &

Abnormalities of posture & gait

R Rigidity

Causes:

P Primary neuronal degeneration (in 75%).

Also called Parkinson’s disease of Paralysis agitans

A After encephalitis & Antidopaminergic drugs

e.g. Chlorpromazine, Haloperidol, Metoclopramide

R Rare causes e.g. Wilson’s disease, some toxins & rare syndromes

Drugs:

P Prodrug of dopamine i.e. Levodopa, usually given along with

Peripheral decarboxylase inhibitors e.g. Carbidopa and Benserazide

A Anticholinergics e.g. Triexiphenidyl and Diphenhydramine

Agonist of dopamine receptor e.g. Bromocriptine

R Releasing dopamine i.e. Amantadine

Retarding dopamine degradation of MAO-B inhibitors e.g. Selegiline

ANTIEPILEPTIC DRUGS

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Classification:

(BHAISAB i.e. elder brother)

B Barbiturates e.g. Phenobarbitone

H Hydantoins e.g. Phenytoin

A Aliphatic carboxylic acid e.g. Valproic acid

I Iminostilbenes e.g. Carbamazepine

S Succinimides e.g. Ethosuccimide

A Adjuvant newer drugs e.g. Lamotrigine, Gamapentin, Vigabatrin, Felbamate

B Benzodiazepines e.g. Clonazepam, Diazepam

Adverse effects of PHENYTOIN:

P Plasma level monitoring needed because of its zero order kinetics

H Hypertrophy of gums, can be minimized by good oral hygiene

E Enzyme induction so interacts with many drugs including other antiepileptics

N Neutropenia and other hypersensitivity reactions

Y Young girls beware! Causes hirsutism, coarsening of facial features and acne

T Teratogenic, married girls beware! Causes foetal hydantoin syndrome

O Osteomalacia due to interference with calcium absorption

I Interference with folate absorption leads to megaloblastic anemia

N Neurological manifestations at higher doses: Ataxia, vertigo and nystagmus

Adverse effects of VALPROATE:

V Vomiting

A Alopecia

L Liver toxicity

P Pancreatitis

R Rashes & thrombocytopenia are rare hypersensitivity reactions

O Oedema

A Ataxia

T Tremors & Teratogenicity, causes neural tube defects

E Each others metabolism increases with Carbamazepine

while it decrease the metabolism of Phenobarbitone & Phenytoin

MOOD STABILIZERS - ANTIMANIC DRUGS

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Mood stabilizer – Antimanic drugs are:

M Main agent i.e. Lithium carbonate

A Alternative agents i.e. Antiepileptics like Carbamazepine & sodium valproate

Side effects of LITHIUM are:

Leukocytes Increased (leukocytosis)

Tremors

Hypothyroidism

Increased Urine (diabetes insipidus)

Moms beware (teratogenic)

ANTIDEPRESSANT DRUGS

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In depression, Tricyclic antidepressants (TCAs) are the drug of choice in severe depression because of their high efficacy while the selective serotonin reuptake inhibitors (SSRIs) are the drug of choice in mild to moderate depression because of their high safety.

The side effects of TCAs are:

T Tremors

C Cardiovascular side effects (arrhythmias esp. in ischemic heart disease, postural hypotension)

A Anticholinergic side effects

(dry mouth, dysphagia, constipation, urinary retention, palpitations,etc.)

S Sedation and Seizures (in predisposed patients)

The side effects of SSRIs are:

S Serotonin syndrome

S Stimulate CNS

R Reproductive dysfunctions if male

I Insomnia

Serotonin syndrome is a very dangerous and fatal situation. It is just like neuroleptic malignant syndrome and results from interaction between serotonin enhancing drugs e.g. SSRIs, MAO-Is, TCAs, etc.

Serotonin syndrome is characterized by (causes HARM):

H Hyperthermia

A Autonomic instability (delirium)

R Rigidity

M Myoclonus

ANTIPSYCHOTIC DRUGS

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Chlorpromazine is the prototype ANTIPSYCHOTIC. Its actions are:

A Antipsychotic effect in psychotic patients (therapeutic effect)

N Neuroleptic syndrome in normal persons (unpleasant effect)

T Temperature control is disturbed

I Increased chances of epileptic fits due to decreased seizure threshold

P Prolactin release increases – galactorrhoea & gynaecomastia

S Side effects – Extrapyramidal

e.g. Parkinsonism, dystonias, akathisia, dyskinesia

Y Yellowness i.e. cholestatic jaundice

C Cholinergic antagonism leading to dry mouth,etc

H Hypotension

O Obesity

T Tolerance to some effects like sedation

I Inhibition of gonadotropin secretion

C Certain spasticity conditions are relieved

ANXIOLYTICS

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Anxiolytics are (‘B’s)

1. Benzodiazepines (sedative)

2. Buspirone (non-sedative; 5-HT_1A partial agonist)

Beta-blockers e.g. Propanolol (for symptomatic control)

SEDATIVES & HYPNOTICS

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Benzodiazepines are the mainstay drugs, Diazepam being the prototype.

DIAZEPAM

Therapeutic effects:

D Delerium tremens (in alcohol withdrawal)

I Insomnia

A Anxiety

E Epilepsy

P Preanaesthetic medication

A As Adjuvant with Antiemetics

M Muscle relaxation

Adverse effects:

D Drowsiness & dizziness (hangover)

I Increased reaction time

A Ataxia

E Epigastric distress

P Paradoxical CNS stimulation

A Abuse liability (due to dependence)

M Memory loss (=amnesia)

SKELETAL MUSCLE RELAXANTS

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Central Muscle Relaxants (C.M.R.)

The drugs are:

C Carisoprodol, Chlorzoxazone, Chlormezanone

M Mephenesin, Meprobamate, Methocarbamol

R Receptor acting drugs increasing GABAergic transmission:

· Benzodiazepines (act on BZD receptors linked with GABA_A receptors)

· Baclofen (act on GABA_B receptors)

Their clinical uses are:

C CNS disorders associated with spasticity

e.g. hemiplegia, paraplegia, multiple sclerosis and cerebral palsy

M Manipulations in Orthopaedics

e.g. setting of fracture and dislocations

R Relieving muscle spasms

e.g. after trauma, tetanus, torticollis and tension & anxiety

PRE-ANAESTHETIC MEDICATIONS

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P R E – Anaesthetic medications are given before anaesthesia to make it more pleasant and safe.

P Pain relied by opioids

e.g. Morphine, Pethidine

R Respiratory & salivary secretion inhibition and prophylaxis of laryngospasm, vagal bradycardia

& hypotension by anticholinergics

e.g. Atropine, Hyoscine, Glycopyrrolate

E Emesis & Gastric-acid regurgitation prevention by Antiemetics

e.g. Metoclopramide, Ondansetron

Acid-Inhibitors

e.g. Ranitidine, Omeprazole

A Anxiolysis by Benzodiazepines

e.g. Diazepam, Midazolam

CHOLINERGIC AND ANTICHOLINERGIC DRUGS

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CHOLINERGIC DRUGS

Acetylcholine (A C h) is the prototype drug.

A Action is nonspecific &

C Cholinesterase enzyme quickly degrades it,

h hence not used clinically.

ANTICHOLINERGIC DRUGS

Atropine is the prototype drug.

(Atropine is obtained from ATROPA belladonna or DHATURA stramonium.)

Clinical uses of Atropine

A As mydriatic-cycloplegic → used topically in refraction testing, fundoscopy and giving rest to

the inflamed eye.

T Traveller’s diarrhea

R Rapid onset mushroom poisoning

O Organophosphorous poisoning

P Preanaesthetic medication

A Arrythmias (brady-arrhythmias)

Adverse effects of Atropine

D Dry mouth → Difficulty in swallowing and speaking

H Hot dry skin & Hypotension

A Accomodation paralysis → blurring of near vision

T Tachycardia

U Urinary retention and (faecal retention) constipation

R Respiratory depression

A Ataxia & Acute congestive glaucoma may precipitate

ADRENERGIC AND ANTIADRENERGIC DRUGS

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ADRENERGIC DRUGS

Adrenaline is the prototype drug. Its clinical uses are:

A Anaphylactic shock (DOC)

B Bronchial asthma

C Cardiac resuscitation

D During local anaesthesia combined with lignocaine

ANTIADRENERGIC DRUGS

Propanolol is the prototype drug.

Its clinical uses are:

(Slap on the face i.e. THAPPAD)

T Thyrotoxicosis & Tremors

H Hypertension & Hypertrophic cardiomyopathy

A Angina & Acute myocardial infarction

P Prophylaxis of migraine

P Pheochromocytoma (along with α-blockers)

A Anxiety & Arrhythmias

D Dissection aortic aneurysm & Digitalis toxicity

Propanolol (including other β-blockers) is contraindicated in:

(Don’t Prescribe Him Propanolol)

D Diabetes mellitus

P Pulmonary Diseases e.g. Angina, COPD

H Heart block or bradycardia

P Prinzmetal’s angina & Peripheral vascular diseases

ADVERSE DRUG REACTIONS

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Adverse drug reactions are classified alphabetically as follows:

A Augmented pharmacological effects: dose dependant

· Side effects → at therapeutic dose

· Toxicity → at high dose

· Intolerance → toxicity at therapeutic dose

B Bizarre effects: non dose dependant

· Drug allergy: 4 types

Anaphylaxis (type I)

Blood cytolysis (type II)

Complex (AG:AB) mediated reaction (type III)

Delayed hypersensitivity (type IV)

· Idiosyncrasy: Abnormal effect e.g. CNS depressants causing stimulation

C Chronic effects: Duration dependant

Adverse effects of prolonged treatment

e.g. Corticosteroids causing immunosuppression

D Delayed effects:

Adverse effects long time after stopping the drug

e.g. Carcinogenicity and Mutagenicity by anticancer drugs and radio-isotopes

E End of treatment effects: Adverse effects due to abruptly stopping the drug e.g. withdrawal

syndrome of clonidine

F Foetal effects: Adverse effects on the foetus depend upon the time of maternal drug intake i.e.

First ½ month → Abortion

From ½ - 2 months → Teratogenicity

2 months onwards → Abnormal growth & development

Drugs causing Agranulocytosis

Agranulocytosis is one of the most severe adverse effects, may be fatal even. Blood cytolysis occurs, especially neutrophils are damaged, predisposing to serious infections.

Following drugs are known to cause AGRANULOCYTOSIS:

A Antithyroid drugs (Propylthiouracil, Carbimazole, Methimazole)

ACE Inhibitors

G Gold salts like Sodium aurothiomalate

R Radioactive elements like I ¹³¹

A Alkylating agents

N Nitrogen mustards like Mechlorethamine, Cyclophosphamide

U Urethane (obsolete)

L Largactil (Chlorpromazine)

O Oxyphenbutazone/Phenylbutazone

C Chloramphenicol & Clozapine

Y Yellow drug i.e. Mepacrine (obsolete)

T Thioureas, Tricyclic antidepressants (TCA)

O Oxazolidine/Phenytoin

S Sulphonamides including Co-trimoxazole

I Indomethacin

S Sulfones, Sulfonylureas (1^st Generation)

Drug interactions (3 ‘P’ s)

Pharmaceutical interactions: during formulation or mixing of drugs. The incompatibility can be due to physical or chemical interaction between the compounds.

Pharmacokinetic interactions: during absorption, distribution, metabolism or excretion of drugs.

Pharmacodynamic interations: at the receptor site of between the actions of the drugs.