1. Introduction to Clinical Pharmacy 🏥

Clinical pharmacy focuses on the patient-centered approach to medication management. As a clinical pharmacist, you work directly with healthcare teams to optimize drug therapy outcomes.

Key Responsibilities of a Clinical Pharmacist:

Drug therapy monitoring and optimization
Patient counseling and medication education
Drug information services to healthcare professionals
Participation in medical rounds and case conferences
Adverse drug reaction monitoring and reporting
Development of formulary and drug use policies

Remember: Clinical pharmacy transforms the role of pharmacists from dispensing professionals to integral members of the healthcare team. Sa hospital setting, ikaw ang expert sa medications!

2. Medication Therapy Management (MTM) 💊

MTM is a systematic approach to optimize drug therapy outcomes. It involves reviewing all medications, identifying problems, and creating action plans.

MTM Component	Description	Example Actions
Medication Therapy Review (MTR)	Comprehensive assessment of all medications	Check for duplications, interactions, appropriateness
Personal Medication Record (PMR)	Complete list of patient's medications	Document Rx, OTC, supplements, herbal products
Medication-Related Action Plan (MAP)	Patient-specific plan to address issues	Simplify regimen, address adherence barriers
Intervention and Referral	Actions taken and follow-up care	Contact physician, schedule follow-up
Documentation and Follow-up	Record keeping and outcome monitoring	Track progress, measure outcomes

💡 Board Exam Tip:

MTM is a billable service in many healthcare systems. Know the 5 core elements and how they apply to patient care scenarios in board exam questions!

3. Drug-Related Problems (DRPs) ⚠️

DRPs are events involving drug therapy that actually or potentially interfere with desired health outcomes. Identifying and resolving DRPs is the core of clinical pharmacy practice.

DRP Category	Description	Clinical Example
Unnecessary Drug Therapy	No medical indication	Antibiotics for viral infection
Needs Additional Therapy	Untreated condition	Diabetic without statin therapy
Ineffective Drug	Not producing desired effect	Antibiotic-resistant organism
Dosage Too Low	Subtherapeutic dose	Subtherapeutic warfarin (INR < 2)
Dosage Too High	Toxic dose	Digoxin toxicity (level > 2 ng/mL)
Adverse Drug Reaction	Harmful effect from drug	ACE inhibitor-induced cough
Drug Interaction	Drug-drug, drug-food interaction	Warfarin + NSAIDs = bleeding risk
Non-adherence	Patient not taking medication	Skipping doses due to cost

Mnemonic: "INDENT ADN" - Indication, Need, Drug selection, Dose, Interactions, Adverse effects, ADherence, New problem

4. Pharmacovigilance and ADR Monitoring 🔍

Pharmacovigilance is the science of detecting, assessing, understanding, and preventing adverse effects from pharmaceutical products.

Types of Adverse Drug Reactions:

Type A (Augmented): Predictable, dose-dependent (e.g., hypoglycemia from insulin)
Type B (Bizarre): Unpredictable, not dose-related (e.g., penicillin allergy)
Type C (Chronic): Long-term use effects (e.g., steroid-induced osteoporosis)
Type D (Delayed): Occurs after time delay (e.g., teratogenicity)
Type E (End of use): Withdrawal effects (e.g., opioid withdrawal)
Type F (Failure): Therapeutic failure (e.g., OCP failure with rifampicin)

Naranjo Algorithm Scoring:

Used to assess causality of ADRs:

Definite: Score ≥ 9
Probable: Score 5-8
Possible: Score 1-4
Doubtful: Score ≤ 0

Questions include: previous reports, timing, dechallenge, rechallenge, alternative causes, etc.

FDA Philippines ADR Reporting:

Healthcare professionals are required to report ADRs to the FDA Philippines Center for Drug Regulation and Research (CDRR). Use Form FDA-ADR for reporting suspected adverse reactions.

5. Drug Interactions Management 💊⚡

Clinical pharmacists must identify, prevent, and manage drug interactions to ensure patient safety.

Interaction Type	Mechanism	High-Yield Examples
Pharmacokinetic	Affects ADME	Rifampicin ↓ warfarin (CYP induction)
Pharmacodynamic	Same or opposite effects	Aspirin + warfarin = ↑ bleeding
Drug-Food	Food affects drug	Grapefruit + statins = toxicity
Drug-Disease	Drug worsens condition	Beta-blockers in asthma

🔥 High-Yield CYP450 Interactions:

CYP3A4 Inhibitors: Ketoconazole, Clarithromycin, Grapefruit juice
CYP3A4 Inducers: Rifampicin, Phenytoin, Carbamazepine
CYP2D6 Inhibitors: Fluoxetine, Paroxetine, Quinidine
CYP2C9 Substrates: Warfarin, Phenytoin, Losartan

6. Therapeutic Drug Monitoring (TDM) 📊

TDM involves measuring drug concentrations to optimize dosing and minimize toxicity, especially for drugs with narrow therapeutic indices.

Drug	Therapeutic Range	Toxic Signs	Monitoring Notes
Digoxin	0.8-2.0 ng/mL	Nausea, yellow vision, arrhythmias	Draw 6-8 hrs post-dose
Phenytoin	10-20 mcg/mL	Nystagmus, ataxia, confusion	Adjust for albumin/renal function
Vancomycin	Trough: 10-20 mcg/mL	Nephrotoxicity, ototoxicity	Draw trough before 4th dose
Aminoglycosides	Peak/Trough varies	Nephrotoxicity, ototoxicity	Extended interval dosing preferred
Lithium	0.6-1.2 mEq/L	Tremor, polyuria, seizures	Draw 12 hrs post-dose
Theophylline	10-20 mcg/mL	Tachycardia, seizures	Many drug interactions

7. Practice Questions 📝

Question 1: Drug-Related Problem

A 65-year-old patient with diabetes and hypertension is taking metformin 500mg BID, lisinopril 10mg OD, and aspirin 80mg OD. He presents with persistent cough for 3 weeks. What is the most likely drug-related problem?

Answer: Adverse Drug Reaction - ACE inhibitor-induced cough. Lisinopril (ACE inhibitor) causes dry, persistent cough in 5-20% of patients due to bradykinin accumulation. Switch to an ARB (e.g., losartan) if cough persists.

Question 2: Therapeutic Drug Monitoring

A patient on vancomycin has a trough level of 25 mcg/mL. What is the appropriate action?

Answer: Hold the next dose and reassess. The level is supratherapeutic (>20 mcg/mL), increasing nephrotoxicity risk. Adjust the dose downward or extend the interval. Monitor serum creatinine.

Question 3: Drug Interaction

A patient on warfarin (INR stable at 2.5) is prescribed clarithromycin for respiratory infection. What should the pharmacist do?

Answer: Alert the physician about significant interaction. Clarithromycin inhibits CYP3A4 and CYP1A2, increasing warfarin levels and bleeding risk. Options: use alternative antibiotic (azithromycin is safer), reduce warfarin dose by 25-50%, or monitor INR closely (every 2-3 days).

Question 4: Naranjo Scale

A patient developed severe skin rash after starting allopurinol. The rash improved after stopping the drug. Using Naranjo algorithm, what causality category is this ADR?

Answer: Probable (Score 5-8). Points for: prior reports (+1), temporal relationship (+2), improvement after withdrawal (+1), reasonable alternative causes ruled out (+2). This is consistent with allopurinol-induced hypersensitivity syndrome.

Clinical Pharmacy