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Drug Catalog Encyclopedia

Your Comprehensive Drug Guide by Pal AI

Explore detailed information about various pharmacological agents, including their mechanisms, uses, side effects, contraindications, and important clinical considerations. Click on any drug name to view its full profile.

Drug Index

Sedatives & Hypnotics

Benzodiazepines GABA-A modulators, increase Cl- channel frequency, safer

Barbiturates Direct GABA-A activation, non-selective, hepatic enzyme inducers, high toxicity

Anti-Epileptic Drugs

Phenytoin Na+ channel blocker, grand mal, gingival hyperplasia, teratogenic

Carbamazepine Na+ channel blocker, grand mal, not for absence, trigeminal neuralgia

Valproic Acid Broad-spectrum, increases GABA, Na+/Ca2+ blocker, teratogenic, hepatotoxic

Ethosuximide Ca2+ (T-type) channel blocker, drug of choice for absence seizures

Anti-Psychotic Drugs

Chlorpromazine Typical, D2 blocker, EPS, NMS

Clozapine Atypical, D4/5-HT2 blocker, agranulocytosis (critical)

Risperidone & Olanzepine Atypical, D2/5-HT2 blockers, less EPS

Opioid Analgesics

Morphine μ agonist, severe pain, respiratory depression, pinpoint pupils, addiction, Naloxone antidote

Codeine Less potent, effective cough suppressant

Meperidine (Pethidine) Less respiratory depression, not antitussive, preferred in obstetrics

Methadone Long-acting, oral, opioid withdrawal treatment

Tramadol Weak μ agonist, mild respiratory depression

Opioid Antagonists

Naloxone Full antagonist, antidote for acute opioid toxicity

Naltrexone Potent, long-acting antagonist, drug of choice for heroin addiction

Mixed Agonists-Antagonists Opioids

Nalorphine κ agonist / μ antagonist, less respiratory depression, no cardiac effects

Nalbuphine & Buprenorphine Analgesia & respiratory depression similar to morphine

Non-Opioid Analgesics

Acetaminophen (Paracetamol) Weak COX inhibitor, analgesic, antipyretic, NO anti-inflammatory, hepatotoxic

Aspirin (ASA) Irreversible COX inhibitor, anti-inflammatory, antiplatelet, Reye's syndrome

Celecoxib Selective COX-2 inhibitor, less GI side effects, higher CV risk

Local Anesthesia

Local Anesthesia (General Concepts) Na+ channel blocker, reversible sensation loss, no consciousness loss

Ester Local Anesthetics Cocaine, Procaine, Tetracaine, plasma metabolism, high allergy risk

Amide Local Anesthetics Lidocaine, Mepivacaine, hepatic metabolism, Lidocaine safe in pregnancy

Cocaine (as Local Anesthetic) Topical only, potent CNS stimulant

Adrenaline with Local Anesthesia Vasoconstrictor, increases duration, reduces toxicity/bleeding, contraindicated in digits

Key Comparisons Between Drug Groups (Your Drug Map)

Feature	Benzodiazepines	Barbiturates
Mechanism of Action	Increase frequency of Cl- channel opening via GABA-A	Direct activation of GABA-A, increase duration of Cl- channel opening
Selectivity	More selective	Non-selective
Safety/Toxic Dose	Relatively safe (lethal dose > 1000x therapeutic)	More toxic (severe respiratory depression)
Hepatic Enzyme Induction	No	Potent inducers of hepatic microsomal enzymes
Dependence	Physical and psychological dependence	Severe physical and psychological dependence

Feature	Typical Antipsychotics	Atypical Antipsychotics
Primary Mechanism	Non-selective D2 blockade	Selective D2 blockade in limbic system and/or 5-HT2 blockade
Extrapyramidal Symptoms (EPS)	Common and severe (e.g., Parkinsonism, dystonia, tardive dyskinesia)	Less common and less severe
Efficacy	Improve positive symptoms	Improve positive and negative symptoms, effective in refractory cases
Examples	Chlorpromazine, Haloperidol	Clozapine, Risperidone, Olanzepine

Feature	Morphine	Meperidine
Respiratory Depression	Severe (main cause of death)	Less than morphine
Antitussive Effect	Yes	No
Use in Obstetrics	Causes fetal addiction & neonatal asphyxia	Preferred (less fetal respiratory depression)
GI Effects	Severe constipation, sphincter of Oddi spasm	Less constipation

Feature	Acetaminophen (Paracetamol)	Aspirin
Anti-inflammatory Effect	None	Potent
COX Inhibition	Weak and unclear	Irreversible COX-1 & COX-2 inhibitor
Platelet Effect	None	Antiplatelet (important for thrombosis prevention)
Hepatotoxicity	Severe hepatotoxicity at toxic doses	Rare hepatotoxicity (except Reye's Syndrome)
Reye's Syndrome	Does not cause	Causes (contraindicated in febrile children)
GI Side Effects	Minimal	Common (irritation, ulcers, bleeding)

Feature	Ester Local Anesthetics	Amide Local Anesthetics
Chemical Linkage	Ester linkage	Amide linkage
Metabolism	By plasma pseudocholinesterase	By hepatic microsomal enzymes
Allergy Risk	Higher (due to PABA production)	Lower
Use in Pregnancy	Mostly contraindicated	Lidocaine is relatively safe

How to Differentiate Between Similar Drugs

Sedatives & Hypnotics:
- Benzodiazepines vs. Barbiturates: Benzodiazepines increase Cl- channel frequency, are safer, and don't induce hepatic enzymes. Barbiturates increase channel duration, are more toxic, and induce hepatic enzymes.
Anti-Epileptic Drugs:
- Phenytoin & Carbamazepine: Both are Na+ channel blockers for grand mal, but not for absence seizures. Phenytoin causes gingival hyperplasia. Carbamazepine causes fluid retention.
- Valproic Acid: The only broad-spectrum drug treating all seizure types.
- Ethosuximide: Drug of choice for absence seizures, acts on T-type Ca2+ channels.
Anti-Psychotic Drugs:
- Typical vs. Atypical: Typicals (e.g., Chlorpromazine) cause more EPS, while Atypicals (e.g., Clozapine, Risperidone) cause less and improve negative symptoms. Clozapine carries agranulocytosis risk.
Opioid Analgesics:
- Morphine: Causes pinpoint pupils and severe respiratory depression, treated by Naloxone.
- Meperidine: Less respiratory depression and preferred in obstetrics.
- Methadone: Used for withdrawal symptoms due to its long duration.
Non-Opioid Analgesics:
- Acetaminophen vs. Aspirin: Acetaminophen has no anti-inflammatory effect and causes hepatotoxicity at high doses. Aspirin is anti-inflammatory and antiplatelet but causes Reye's Syndrome in children and GI side effects.
- Selective COX-2 inhibitors (e.g., Celecoxib): Fewer GI side effects but higher cardiovascular risk.
Local Anesthesia:
- Esters vs. Amides: Esters (e.g., Procaine) are metabolized in plasma and have a higher allergy risk. Amides (e.g., Lidocaine) are metabolized in the liver.
- Lidocaine: The only local anesthetic relatively safe in pregnancy.
- Adrenaline with LA: Increases duration and reduces toxicity, but contraindicated in digits (fingers, toes, penis) due to gangrene risk.