🦴 Module 6 · Bone & Skin Disorders

🧵 Exam traps ⭐ HIGH YIELD

• Allopurinol PREVENTS gout; colchicine TREATS it. Giving allopurinol to abort an active flare is the classic wrong answer.
• Calcitonin LOWERS calcium; calcitriol (vitamin D) RAISES it. The names differ by one syllable and the effects are opposite.
• Raloxifene protects bone but raises VTE risk and causes hot flashes. It is not 'estrogen without side effects.'
• Hydroxychloroquine's signature monitoring is the eye exam, not the CBC. Students default to blood work and lose the point.
• Benzoyl peroxide bleaches towels, pillowcases, clothing, and hair. That is a teaching point, not trivia.
• Topical steroid potency matters: high-potency products are for thick skin for short periods and are never used on the face, groin, or a child's diaper area.

What are the pharmacological treatment options for acne?⭐ HIGH YIELD

Treatment steps up with severity. Mild: topical benzoyl peroxide and a topical retinoid (tretinoin, adapalene, tazarotene). Mild to moderate inflammatory: add a topical antibiotic (clindamycin, erythromycin) or azelaic acid. Moderate: oral antibiotics (doxycycline, minocycline) plus hormonal therapy (combined oral contraceptives, spironolactone). Severe nodulocystic or refractory: oral ISOTRETINOIN.

• Never use a topical antibiotic alone. Always pair it with benzoyl peroxide to prevent bacterial resistance.
• Retinoids: apply at NIGHT, a pea-sized amount to dry skin. Expect initial worsening and peeling, and require daily sunscreen.
• ISOTRETINOIN is a severe TERATOGEN (pregnancy category X): iPLEDGE enrollment, two forms of contraception, two negative pregnancy tests before starting, and monthly testing. Monitor triglycerides, LFTs, and mood.
• Doxycycline: photosensitivity and esophagitis. Take with a full glass of water, stay upright 30 minutes, avoid dairy, antacids, and iron within 2 hours. Avoid in pregnancy and children under 8.
• Benzoyl peroxide bleaches towels, pillowcases, and clothing.

Isotretinoin = 'iso-TERATOGEN': two contraceptives, two pregnancy tests, iPLEDGE.

What are the pharmacological treatment options for psoriasis?⭐ HIGH YIELD

Topical first: high-potency corticosteroids, vitamin D analogs (calcipotriene), topical retinoids (tazarotene), coal tar, calcineurin inhibitors, and salicylic acid. Then phototherapy (UVB, PUVA). For moderate to severe disease or joint involvement: systemic methotrexate, cyclosporine, acitretin, apremilast, or BIOLOGICS.

• Calcipotriene combined with betamethasone is a very common first-line topical product.
• Biologics: adalimumab, etanercept, infliximab (TNF inhibitors); secukinumab, ixekizumab (IL-17); ustekinumab, guselkumab (IL-12/23 and IL-23). Screen for TB and hepatitis first, hold during active infection, and give no live vaccines.
• Methotrexate is dosed WEEKLY, never daily. Supplement folic acid, monitor CBC and LFTs, avoid alcohol, and it is teratogenic.
• Acitretin and tazarotene are teratogenic. Acitretin requires contraception for 3 years after stopping and complete alcohol avoidance.
• Systemic corticosteroids are generally AVOIDED in psoriasis: stopping them causes a rebound pustular flare.

Methotrexate is WEEKLY, not daily. That mix-up is the classic fatal medication error.

What are the pharmacological treatment options for acute gout and prophylaxis of gout?⭐ HIGH YIELD

ACUTE flare: NSAIDs (indomethacin, naproxen), colchicine, or corticosteroids (oral, IV, or intra-articular). PROPHYLAXIS: urate-lowering therapy with allopurinol or febuxostat (xanthine oxidase inhibitors) or probenecid (uricosuric), plus low-dose colchicine or an NSAID as cover for the first 3 to 6 months.

• Allopurinol plus azathioprine or 6-mercaptopurine causes severe toxicity because allopurinol blocks their breakdown.
• Allopurinol rash can progress to Stevens-Johnson syndrome. Report any new rash immediately.
• Starting urate-lowering therapy can PRECIPITATE a flare, which is why colchicine or NSAID cover is layered on.
• Avoid low-dose aspirin and thiazide or loop diuretics when possible; they raise uric acid.
• Teach: 2 to 3 L fluid daily, limit purines (organ meat, shellfish, red meat), limit alcohol especially beer, and limit high-fructose drinks.

Allopurinol PREVENTS, colchicine and NSAIDs RELIEVE. Never start the preventer mid-attack.

What are the adverse effects of corticosteroid use?⭐ HIGH YIELD

Corticosteroids produce a Cushingoid picture: hyperglycemia, weight gain with moon face and buffalo hump, hypertension and fluid retention, osteoporosis, immunosuppression with masked infection, GI ulceration, mood changes, cataracts and glaucoma, thin skin with poor wound healing, and muscle wasting. Because they cause adrenal suppression they must be TAPERED, never stopped abruptly.

• Metabolic: hyperglycemia (monitor glucose even in non-diabetics), hypokalemia, sodium and water retention.
• Infection: fever and redness are blunted, so a patient who looks fine can be septic. No live vaccines on high doses.
• Bone: long-term use causes osteoporosis. Add calcium, vitamin D, weight-bearing exercise, and consider a bisphosphonate. GI: give with food, and add a PPI or H2 blocker if the patient is also on NSAIDs.
• Abrupt discontinuation causes ADRENAL CRISIS: hypotension, hypoglycemia, weakness, and shock. Stress doses are needed for illness or surgery.
• Teaching: take in the MORNING to mimic the natural cortisol rhythm, never skip or double a dose, and carry medical alert identification.

Steroids give you Cushing's on purpose: high sugar, high pressure, high infection risk, low bone, low potassium. And taper, always taper.

Benzoyl peroxide

Benzoyl peroxide is a topical antibacterial and keratolytic for acne. It kills Cutibacterium acnes, dries and unplugs the follicle, and prevents antibiotic resistance when paired with a topical antibiotic.

• Expect dryness, peeling, redness, and stinging. Start once daily at a low strength (2.5 to 5%) and build up.
• It BLEACHES hair, towels, pillowcases, and clothing. Use white linens and warn the patient in advance.
• Do not apply at the same time of day as tretinoin, which it can inactivate. Benzoyl peroxide in the morning, retinoid at night.
• Causes photosensitivity, so daily sunscreen is required.
• Rare but serious hypersensitivity: throat tightness, faintness, facial swelling. Stop and seek care. Takes 4 to 8 weeks to see results. Adherence is the biggest barrier.

Benzoyl peroxide bleaches everything but your patience. White towels only.

Calcipotriene

Calcipotriene (Dovonex) is a topical VITAMIN D ANALOG for plaque psoriasis. It slows the excessive proliferation of keratinocytes and normalizes skin cell differentiation.

• Apply a thin layer to the plaques only. Avoid the face, groin, and skin folds because of irritation.
• Do NOT exceed the recommended weekly amount (about 100 g/week). Systemic absorption causes HYPERCALCEMIA: nausea, weakness, confusion, polyuria, and arrhythmias.
• Wash hands after applying unless the hands are the treated area.
• It is inactivated by salicylic acid and some acidic topicals, so apply products separately.
• Often combined with betamethasone. Expect 2 weeks for initial benefit and 6 to 8 weeks for full effect.

Calcipotriene = calcium plus psoriasis. Too much cream means too much calcium.

Permethrin (What administration instructions and education points should be provided to the⭐ HIGH YIELD

Permethrin is a topical scabicide and pediculicide that is neurotoxic to the parasite. For SCABIES use 5% cream: apply to the entire body from the NECK DOWN, leave on 8 to 14 hours, wash off, and repeat in 7 days. For HEAD LICE use the 1% cream rinse on clean, towel-dried hair for 10 minutes.

• In infants and young children, also apply to the scalp, hairline, temples, and forehead. Approved from 2 months of age. Do not miss: between fingers and toes, under the nails (trim and scrub), wrists, waistline, umbilicus, groin, and buttock folds.
• Treat ALL household members and close contacts at the same time, even if they have no symptoms.
• Wash bedding, clothing, and towels in HOT water and dry on high heat. Seal non-washables in a plastic bag for 3 to 7 days.
• ITCHING CAN CONTINUE FOR 2 TO 4 WEEKS after successful treatment. That is a reaction to dead mites, not treatment failure. Do not apply extra doses.
• Avoid eyes and mucous membranes. Mild burning, stinging, and temporary increased itching are expected.

Neck down, 8 to 14 hours, repeat in a week, and the itch outlives the mite.

Tazarotene⭐ HIGH YIELD

Tazarotene (Tazorac) is a topical RETINOID used for psoriasis and acne. It normalizes keratinocyte turnover and reduces inflammation. It is PREGNANCY CATEGORY X and is absolutely contraindicated in pregnancy.

• Confirm a negative pregnancy test and effective contraception before starting it in anyone of childbearing potential.
• Apply a thin, pea-sized layer at BEDTIME to dry skin, and wash hands afterward.
• Expect burning, stinging, redness, peeling, and dryness, worst in the first few weeks.
• Strong PHOTOSENSITIVITY: daily broad-spectrum sunscreen, protective clothing, no tanning beds, and caution if combined with phototherapy.
• Do not apply to eczematous, sunburned, or broken skin, and keep it away from eyes, mouth, and mucous membranes. Do not layer with other drying agents (benzoyl peroxide, salicylic acid, alcohol-based products) at the same application.

Every retinoid: night, sunscreen, and NOT in pregnancy.

💉 Alendronate

Bone-resorption inhibitor, Bisphosphonate

Treatment and prevention of osteoporosis in postmenopausal women, treatment of osteoporosis in men, Paget’s disease, treatment of corticosteroidinduced osteoporosis in postmenopausal women not receiving estrogen and in men who are on continuing corticosteroid …

Decreases rate of bone resorption and may directly block dissolution of hydroxyapatite crystals of bone; inhibits osteoclast activity

• RESP Asthma exacerbation
• CV Atrial fibrillation
• INTEG Rash, photosensitivity
• CNS Headache
• GI Abdominal pain, constipation, nausea, vomiting, esophageal ulceration, acid reflux, dyspepsia, esophageal perforation, diarrhea, esophageal cancer
• META Hypophosphatemia, hypocalcemia
• MS Bone pain …

• To remain upright for 30 min after dose to prevent esophageal irritation; if dose is missed, skip dose, do not double doses or take later in day; to take in am before foo …
• To take calcium, vitamin D if instructed by health care provider
• To use sunscreen, protective clothing to prevent photosensitivity
• To avoid smoking, alcohol intake, which increase osteoporosis

💉 Allopurinol

Antigout drug, antihyperuricemic, Xanthine oxidase inhibitor

Chronic gout, hyperuricemia associated with malignancies, recurrent calcium oxalate calculi, uric acid calculi

Inhibits the enzyme xanthine oxidase, reducing uric acid synthesis

• GI Nausea, vomiting, malaise, diarrhea, hepatitis
• INTEG Rash
• CV Hypo- and hypertension, HF (IV use)
• CNS Drowsiness
• GU Renal failure
• MISC Hypersensitivity, bone marrow depression
• MS Acute gouty attack

• To take as prescribed; if dose is missed, take as soon as remembered; do not double dose; tablets may be crushed
• To increase fluid intake to 2 L/day
• To report skin rash, stomatitis, malaise, fever, aching; product should be discontinued
• To avoid hazardous activities if drowsiness or dizziness occurs

💉 Calcitriol

Parathyroid agent (calcium regulator), Vitamin D hormone

Hypocalcemia with chronic renal disease, hyperparathyroidism, pseudohypoparathyroidism, renal osteodystrophy; plaque psoriasis (TOP)

Increases intestinal absorption of calcium; provides calcium for bones; increases renal tubular reabsorption of phosphate

• CNS Drowsiness, headache, vertigo
• CV Hypertension, dysrhythmias, edema
• EENT Blurred vision, photophobia, rhinorrhea
• ENDO Hypercalcemia
• GI Nausea, vomiting, jaundice, anorexia, dry mouth, constipation, cramps, metallic taste, pancreatitis
• GU Polyuria
• MS Myalgia, arthralgia …

• About symptoms of hypercalcemia: renal stones, nausea, vomiting, anorexia, lethargy, thirst, bone or flank pain, confusion
• To follow prescribed diet, to avoid products with sodium: cured meats, dairy products, cold cuts, olives, beets, pickles, soups, meat tenderizers with chronic renal failu …
• To avoid OTC products that contain calcium, potassium, sodium with chronic renal failure, to take as prescribed, not to double or skip doses
• To monitor weight weekly; to maintain fluid intake

Antidote / reversal: 1

💉 Colchicine

Antigout agent, Alkaloid

Gout, gouty arthritis (prevention, treatment); to arrest the progression of neurologic disability in those with MS, Mediterranean fever Unlabeled: Bechet syndrome with arthritis, cutaneous lesions or mucocutaneous ulcers …

Inhibits microtubule formation of lactic acid in leukocytes, which decreases phagocytosis and inflammation in joints

• GI Nausea, vomiting, anorexia, cramps
• HEMA Agranulocytosis, thrombocytopenia, aplastic anemia, pancytopenia
• MISC Alopecia, peripheral neuritis

• To avoid alcohol, OTC preparations that contain alcohol
• To report any pain, redness, hard areas, usually in legs; rash, sore throat, fever, bleeding, bruising, weakness, numbness, tingling, nausea, vomiting, abdominal pain, mu …
• To avoid grapefruit and juice, may increase colchicine level
• About the importance of complying with medical regimen (diet, weight loss, product therapy); about the possibility of bone marrow depression occurring; not to double or s …

Antidote / reversal: 1

💉 Hydroxychloroquine (What laboratory monitoring is recommended for this medication?)

Antimalarial, antirheumatic (DMARDs), 4-Aminoquinoline derivative

Malaria caused by susceptible strains of Plasmodium vivax, P. malariae, P. ovale, P. falciparum (some strains); SLE, rheumatoid arthritis Unlabeled: Lupus nephritis, polymorphous-light eruptions

Impairs complement-dependent antigen–antibody reactions

• CNS Headache, fatigue, irritability, seizures, bad dreams, dizziness, confusion, psychosis, anxiety, suicidal ideation
• CV HF, torsades de pointes, QT prolongation, asystole with syncope
• EENT Blurred vision, corneal changes, tinnitus, vertigo, nystagmus, corneal deposits
• GI Nausea, vomiting …

• To use sunglasses in bright sunlight to decrease photophobia; to wear protective clothing (photosensitivity)
• That urine may turn rust or brown; that skin may become blue-black
• To report hearing, visual problems, fever, fatigue, bruising, bleeding, which may indicate blood dyscrasias
• RA: To report to provider if there is no change in condition, may need several months for results

Antidote / reversal: 1

💉 Prednisone

Corticosteroid, Intermediate-acting glucocorticoid

Severe inflammation, neoplasms, multiple sclerosis, collagen disorders, dermatologic disorders, pulmonary fibrosis, asthma

Decreases inflammation by increasing capillary permeability and lysosomal stabilization, minimal mineralocorticoid activity

• CNS Depression, flushing, sweating, headache, mood changes
• CV Hypertension, thrombophlebitis, embolism, tachycardia, fluid retention
• EENT Fungal infections, increased intraocular pressure, blurred vision
• GI Diarrhea, nausea, abdominal distention, GI hemorrhage, increased appetite …

• That emergency ID as corticosteroid user should be carried; provide information about product being taken and condition
• To notify prescriber if therapeutic response decreases; that dosage adjustment may be needed
• To avoid vaccinations
• Not to discontinue abruptly; adrenal crisis can result

💉 Sulfasalazine

GI antiinflammatory, antirheumatic (DMARD), Sulfonamide

Ulcerative colitis; RA; juvenile RA (Azulfidine EN-tabs)

Prodrug to deliver sulfapyridine and 5-aminosalicylic acid to colon; antiinflammatory in connective tissue also

• CNS Headache, neuropathy
• GI Nausea, vomiting, abdominal pain, stomatitis, hepatitis, glossitis, pancreatitis, diarrhea
• GU Orange-colored urine
• HEMA Leukopenia, neutropenia, thrombocytopenia, agranulocytosis, hemolytic anemia
• INTEG Rash, dermatitis, urticaria, Stevens-Johnson syndrome …

• To take each oral dose with full glass of water to prevent crystalluria
• That contact lenses, urine, skin may be yellow-orange
• To avoid sunlight or use sunscreen to prevent burns
• To notify prescriber of skin rash, sore throat, fever, mouth sores, unusual bruising, bleeding

💉 Acyclovir

Antiviral, Purine nucleoside/nucleotide analog

Mucocutaneous herpes simplex virus, herpes genitalis (HSV-1, HSV-2), varicella infections, herpes zoster, herpes simplex encephalitis, herpes labialis

Converted to acyclovir monophosphate by virus-specific thymidine kinase then further converted to acyclovir triphosphate by other cellular enzymes, inhibits viral DNA synthesis

• CNS Tremors, confusion, lethargy, hallucinations, seizures, dizziness, headache, encephalopathic changes
• EENT Gingival hyperplasia
• GI Nausea, vomiting, diarrhea, increased ALT/AST, abdominal pain, colitis
• GU Hematuria, acute renal failure …

• To take as prescribed; if dose is missed, take as soon as remembered up to 1 hr before next dose; do not double dose
• That product may be taken orally before infection occurs; product should be taken when itching or pain occurs, usually before eruptions
• That sexual partners need to be told that patient has herpes because they can become infected; condoms must be worn to prevent reinfections
• Not to touch lesions to avoid spreading infection to new sites, not to use topical products on lesions, spreading may occur

Antidote / reversal: 1

💉 Betamethasone

Corticosteroid, topical

Inflammation/itching corticosteroid-responsive dermatoses on the skin/scalp

Crosses cell membrane to attach to receptors to decrease inflammation, itching; inhibits multiple inflammatory cytokines

• INTEG Burning, folliculitis, pruritus, dermatitis, maceration, erythema
• MISC Hyperglycemia, glycosuria, Cushing’s syndrome, HPA axis suppression

• Topical route:
• That betamethasone valerate may be used with occlusive dressings for psoriasis or recalcitrant conditions; not to use dipropionate with occlusive dressings
• Avoid use of topical corticosteroids on face
• Cream/ointment/lotion:

💉 Clotrimazole

Topical antifungal, Imidazole derivative

Vulvovaginal, oropharyngeal candidiasis; topical fungal infections, prevention of oropharyngeal candidiasis in immunocompromised

Antifungal activity results from altering cell wall permeability

• GI Nausea, vomiting
• GU Vaginal burning, irritation
• INTEG Burning, peeling, rash, pruritus

• Topical route:
• That topical skin products are not for intravaginal therapy and are for external use only; do not use skin products near the eyes, nose, or mouth; do not use occlusive dr …
• To wash hands prior to and after use; wash affected area and gently pat dry
• Cream: to shake well before use; apply a thin film to the cleansed affected area; massage gently into affected areas

💉 Finasteride (What is the mechanism of action for this drug?)

Hormone, androgen inhibitor, hair stimulant, 5-α-Reductase inhibitor

Symptomatic benign prostatic hyperplasia (Proscar); male-pattern baldness (Propecia)

Inhibits 5-α-reductase and reduction in DHT; DHT induces androgenic effects by binding to androgen receptors in the cell nuclei of the prostate gland, liver, skin; prevents development of BPH

• GU Impotence, decreased libido, decreased volume of ejaculate, sexual dysfunction, gynecomastia
• INTEG Rash
• MISC Breast tenderness, secondary malignancy, angiedema

• That volume of ejaculate may be decreased during treatment; that impotence and decreased libido may also occur and may continue after discontinuing treatment
• That Propecia results may not occur for 3 mo
• That Proscar results may not occur for 6-12 mo
• Advise patient to take as directed, not to skip or double doses, up to 12 mo may be required

💉 Minocycline

antiinfective, Tetracycline

Acinetobacter sp., Actinomyces israelii, Actinomyces sp., Bacillus anthracis, Bartonella bacilliformis, Bordetella pertussis, Borrelia burgdorferi, Borrelia recurrentis, Brucella sp., Burkholderia mallei, Burkholderia pseudomallei, Campylobacter fetus …

Inhibits protein synthesis, phosphorylation in microorganisms by binding to ribosomal subunits, reversibly binding to ribosomal subunits; bacteriostatic

• CNS Dizziness, fever, light-headedness, vertigo, seizures, increased intracranial pressure, headache
• CV Pericarditis, thrombophlebitis
• EENT Permanent discoloration of teeth, oral candidiasis, tinnitus
• GI Nausea, vomiting, diarrhea, anorexia, hepatotoxicity …

• To avoid sunlight, wear protective clothing; that sunscreen does not seem to decrease photosensitivity
• That all prescribed medication must be taken to prevent superinfection; not to use outdated product because Fanconi’s syndrome may occur
• To report diarrhea that can occur several months after discontinuing product
• To avoid taking antacids, iron, cimetidine; to use 2 hr before, 6 hr after this product, absorption may be decreased; to take with a full glass of water; to take with foo …

💉 Minoxidil

Antihypertensive, Vasodilator, peripheral

Topically to treat alopecia

💉 Mupirocin

Topical antiinfective

Impetigo, skin lesions (Staphylococcus aureus/Streptococcus pyogenes)

Antibacterial activity results from inhibition of protein synthesis; bacteriostatic at low concentration, bactericidal at high concentration

• CNS Headache
• GI Taste change, nausea
• INTEG Burning, rash, pruritus

• Topical route
• Not to use skin products near the eyes, nose, or mouth
• To wash hands before and after use and to wash affected area and gently pat dry
• Cream/ointment: to apply a thin film to the cleansed affected area; to cover treated areas with gauze dressing if desired