NAPLEX Study Guide

#NAPLEX #pharmacy #medicine #statins

💊Key details - Cancer Myelosuppression Treatment Cancer therapy–induced myelosuppression: NEUTROPENIA: Granulocyte colony-stimulating factors include: 🔸filgrastim 🔸pegfilgrastim They act on myeloid progenitors via the G-CSF receptor to accelerate neutrophil proliferation, differentiation, and release from the bone marrow. ➡️Pegylation prolongs half-life and allows once-per-cycle dosing. These agents reduce febrile neutropenia risk but can cause bone pain and, rarely, splenic complications. ANEMIA: Chemotherapy-induced anemia is addressed with erythropoiesis-stimulating agents such as: 🔸epoetin alfa 🔸darbepoetin alfa These drugs activate erythropoietin receptors on erythroid progenitors to increase erythrocyte production. However, their use is restricted due to risks of thromboembolism and potential tumor progression, and they are generally reserved for palliative settings with careful hemoglobin targets. THROMBOCYTOPENIA: 🔸Oprelvekin: a recombinant human IL-11 drug used to prevent severe thrombocytopenia and reduce the need for platelet transfusions. It acts as a thrombopoietic growth factor that stimulates the bone marrow to produce more megakaryocytes and platelets.

💊Key Details - Upadacitinib Upadacitinib is a selective Janus kinase (JAK1) inhibitor that reduces inflammation by blocking cytokine signaling involved in immune responses: ☑️Indications: autoimmune conditions such as rheumatoid arthritis, atopic dermatitis, and ulcerative colitis. ☑️Mechanism: by inhibiting JAK-STAT pathways, it decreases production of pro-inflammatory mediators. ☑️Adverse effects: upper respiratory tract infections, fever, thrombosis, and an increased risk of malignancy. ☑️Boxed warning: upadacitinib carries a boxed warning for serious heart-related events, cancer, blood clots, and death. ☑️Interactions: drugs that strongly inhibit CYP 3A4 increase upadacitinib levels. ☑️Brand name: Rinvoq

💊Otitis Media - Drug Treatment Options First-line treatment for acute otitis media in both adults and children is amoxicillin, due to its effectiveness against common pathogens such as Streptococcus pneumoniae and Haemophilus influenzae. In cases of penicillin allergy, alternatives like macrolides may be used, though resistance can be an issue. If symptoms persist or the infection is treatment-resistant, amoxicillin-clavulanate is typically recommended to cover β-lactamase–producing organisms, with other options including cephalosporins or intramuscular ceftriaxone in more severe cases.

💊Why is piperacillin effective against P. aeruginosa? It's due to structural modifications of the penicillin side chain that enhance penetration into Gram-negative bacteria, particularly Pseudomonas aeruginosa. Specifically, its ureido side chain increases polarity and mimics peptide substrates, allowing better passage through porin channels and stronger binding to penicillin-binding proteins (PBPs). This improves activity against difficult-to-treat Gram-negative organisms compared to earlier penicillins, though it is still often combined with a β-lactamase inhibitor to prevent enzymatic degradation.

💊TMP-SMX Dosing - Urinary Tract Infections For uncomplicated urinary tract infections (UTIs), trimethoprim-sulfamethoxazole (TMP-SMX) is typically dosed as: Standard dose: 1 double-strength (DS) tablet (160 mg trimethoprim / 800 mg sulfamethoxazole) every 12 hours for 3 days. Key points: ☑️Short-course (3-day) therapy is typical for uncomplicated cystitis in otherwise healthy patients. ☑️Longer durations (7–14 days) may be used for complicated UTIs or in certain patient populations. ☑️Dose adjustments may be needed in renal impairment.

💊Tetracycline + Isotretinoin Interaction Both isotretinoin and tetracyclines can independently increase intracranial pressure. Co-administration of the two drugs significantly raises the risk of pseudotumor cerebri. 👉Pseudotumor cerebri is often known as idiopathic intracranial hypertension. Symptoms include: ☑️headache ☑️visual disturbances ☑️ringing in the ears ☑️vision loss (due to pressure on optic nerves)

💊Long-Term Effects of HAART Therapy Long-term therapy with HAART (highly active antiretroviral therapy) can produce metabolic and organ-related effects including: ☑️lipodystrophy ☑️dyslipidemia ☑️insulin resistance ☑️hepatotoxicity ☑️reduced bone mineral density Some older nucleoside reverse transcriptase inhibitors may also cause mitochondrial toxicity, which contributes to complications such as lactic acidosis and peripheral neuropathy. They are also associated with a higher risk of other effects such as lipodystrophy. These drugs include: ☑️stavudine ☑️didanosine ☑️didovudine Modern HAART regimens use these agents much less frequently because newer drugs (e.g. tenofovir or lamivudine) have significantly lower mitochondrial toxicity risk.

💊Loperamide Risks Loperamide is a peripherally acting μ-opioid receptor agonist used for diarrhea, but high doses can cause serious cardiac toxicity 👇 ☑️Excessive use or misuse may lead to QT prolongation, torsades de pointes, and other life-threatening ventricular arrhythmias due to effects on cardiac ion channels. ☑️Although it normally does not cross the blood–brain barrier significantly, very high doses or drug interactions can produce central opioid effects and have been associated with misuse. ☑️The risk is increased when combined with drugs that inhibit CYP3A4, CYP2C8, or P-glycoprotein, which can raise loperamide concentrations.

💊Zoliflodacin - Key Details Zoliflodacin is a first-in-class spiropyrimidinetrione antibacterial drug that inhibits bacterial DNA gyrase (GyrB subunit) - disrupting DNA replication and transcription: ☑️It was FDA approved in December 2025 for the treatment of uncomplicated gonorrhea, including strains resistant to current therapies. ☑️Unlike fluoroquinolones, it targets a different binding site on DNA gyrase, which helps retain activity against resistant bacteria. Brand name: Nuzolvence ®

💊Phenytoin dosing in status epilepticus: A loading dose of 15 – 20 mg/kg IV is given (maximum infusion rate 50 mg/min in adults). This is followed by a maintenance dose of ~5 – 7 mg/kg/day divided into doses once seizures are controlled.

💊Rifampin and Red-Orange Urine, Tears, Sweat Why does rifampin cause this effect? ☑️The drug contains a highly conjugated chromophore structure (a naphthoquinone-based ring system) that strongly absorbs light and gives the molecule its characteristic reddish-orange pigment. ☑️After oral administration, rifampin is absorbed and metabolized in the liver to active metabolites such as desacetylrifampicin, which retain this pigment. ☑️Both the parent drug and its metabolites are eliminated through renal excretion and biliary secretion, meaning they pass into urine, sweat, saliva, and tears. ☑️Because the molecules themselves remain colored during excretion, bodily fluids take on an orange-red appearance. ☑️The effect is harmless and expected, but patients should be counseled because the pigment can stain clothing and permanently discolor soft contact lenses.

💊Green Tea & Nadolol Interaction Green tea can significantly reduce the absorption of nadolol, a nonselective beta-blocker, by inhibiting intestinal uptake transporters known as OATP (organic anion transporting polypeptides). This decreases nadolol’s bioavailability and may reduce its blood pressure–lowering effect. Patients taking nadolol should avoid drinking green tea around the time of dosing to prevent reduced therapeutic response. ❌Green tea has not been shown to interact with other beta-blockers to the same degree.

💊Lennox-Gastaut Syndrome Lennox-Gastaut syndrome (LGS) is a severe, childhood-onset epilepsy characterized by multiple seizure types (including tonic and atonic seizures), cognitive impairment, and a slow spike-and-wave pattern on EEG. What drugs are typically used? First-line treatment is typically valproate - often in combination with other anticonvulsant drugs, such as lamotrigine and rufinamide, as LGS is usually resistant to a single medication. Alternative add-on drugs used: 🔸clobazam 🔸topiramate

💊Drugs & Optic Neuropathy Several drugs are associated with causing optic neuropathy - a condition involving damage to the optic nerve that can lead to blurred vision, decreased visual acuity, color vision changes, or permanent vision loss. Today, we review some of the most common examples: 1⃣ Ethambutol can cause dose-related optic neuritis, particularly with prolonged use. 2⃣ Isoniazid has also been implicated, though less commonly. 3⃣ Amiodarone has been associated with optic neuropathy, sometimes presenting similarly to non-arteritic ischemic optic neuropathy. 4⃣ Linezolid can cause optic and peripheral neuropathy, especially with extended therapy beyond 28 days. 5⃣ Sildenafil has been linked in rare cases to non-arteritic anterior ischemic optic neuropathy (NAION). 6⃣ Metronidazole, particularly with prolonged use or high cumulative doses, can cause optic neuropathy and optic neuritis - though this is very rare.

Epinephrine is widely used during cardiac arrest because it increases vascular tone, blood pressure, and heart rate, improving the likelihood of return of spontaneous circulation (ROSC). Yet its role remains contested. Evidence from the PARAMEDIC2 trial and later analyses showed that although epinephrine improves ROSC rates, it does not lead to better neurologic recovery and may adversely affect cerebral microcirculation while promoting platelet aggregation. These findings have sharpened clinical and ethical debate over whether improved short-term survival justifies potential harm to neurologic outcomes. mdsc.pe/4tY3i99

👉Individual Statins and Myopathy Risk All statins carry a risk of myopathy and, rarely, rhabdomyolysis, but the risk is higher with higher doses and certain statins: ✔️Simvastatin, particularly at the 80 mg dose, has been strongly associated with increased muscle toxicity. ✔️Atorvastatin and lovastatin also carry higher risk at elevated doses or when combined with CYP3A4 inhibitors. ✔️In contrast, pravastatin and fluvastatin tend to have lower rates of muscle-related adverse effects. ⚠️Risk increases with advanced age, renal impairment, hypothyroidism, and interacting drugs (e.g. strong CYP3A4 inhibitors).

Antibacterial drugs, first-line agents 👇

◻️Leflunomide - Rheumatoid Arthritis Dosage Loading dose: 100 mg orally once a day for 3 days Maintenance: 20 mg orally once a day (If not well tolerated, the dose may be decreased to 10 mg orally once a day)

Repatha Patient Tips: 7 Things You should Know #bottom-line" target="_blank" rel="nofollow noopener">drugs.com/tips/repatha-p…

💊NAPLEX MedFact. Some drugs can have a negative impact on the quality or texture of hair. Five key examples include: 1⃣ Isotretinoin Can cause dry, brittle hair May lead to temporary hair thinning Effects are usually reversible after discontinuation 2⃣ Warfarin Associated with hair thinning or shedding in rare cases, at least 3-4 months after starting treatment Typically causes diffuse (all-over) hair loss 3⃣Valproic acid May cause hair thinning, texture changes (curlier hair than before), or hair loss Sometimes linked to changes in hair color, too 4⃣ Methotrexate Can cause hair thinning or mild alopecia More common at higher doses 5⃣ Propranolol Rarely associated with telogen effluvium (stress-related shedding) Hair loss is typically reversible