Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
CaHomeostasisDrugs
lecture 25 maalouf
| Question | Answer |
|---|---|
| the most important measure for tx in pts with mild to moderate hypercalcemia | hydration. IV saline up to 3-4L/day. can give Lasix to supplement calciuresis once pt is hydrated |
| tx methods for severe hypercalcemia of malignancy | may hydrate & give diuretics, but also add parenteral bisphosphonates like pamidronate and zoledronate |
| oral Ca supplements | Ca-carbonate has best bioavailability, requires gastric acid to dissolve // Ca-citrate works independently of gastric acid but has lower bioavailability = more pills // Ca-lactate - worst bioavailability |
| cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2) | oral vitamin D preparations that require a functional kidney to metabolize them to the bioeffective form 1,25-(OH)2D. D3 is in OTC MVs and D2 has long half-life, is inxpensive |
| calcitriol aka 1,25-(OH)2D | most expensive oral vitamin D supplement, has a short-half life but acts most quickly and doesn't require metabolism for activity. optimal choice for renal failure pts. in those with severe hypocalcemia (<6 mg/dL) add IV Ca-gluconate |
| thiazide diuretics | inhibit calciuresis (opposite of loop diuretics) and can be given along with Ca and vitamin D supplements in hypocalcemic pts |
| Cinacalcet (Sensipar), approved for those with parathyroid carcinoma, those with parathyroid adenomas who aren't surgical candidates and those with hypercalcemia who also have renal failure | allosteric activator of the CaSR. is lipophilic/hydrophobic thus absorbed rapidly after oral administration. peak plasma levels achieved in 60 –90 min. lowers plasma PTH levels rapidly |
| the only anabolic bone drug approved by the FDA | teriparatide or Forteo is rPTH that stimulates the receptor, which if continuous over time leads to resorption of bone; however, if given in a pulsatile fashion it actually leads to bone creation |
| bisphosphonates | have high affinity for Ca-hydroxyapatite and exhibit antiresorptive activities. 3rd generation drugs risendronate, ibandronate and zoledronate have ~ 10Kx more potency than 1st generation ones. target cancellous bone best and inc BMD of spine/hip |
| mechanism of action of 1st vs 2nd/3rd generation bisphosphonates | 1st: caused osteoclast apoptosis after they were converted into toxic metabolites // 2nd/3rd: modulate osteoclastic activity instead of killing it. inhibit GPP or FPP synthase |
| pharmacokinetics of bisphosphonates | absorbed poorly from GI tract ~ 1%/dose with oral meds. must be given on an empty stomach. excreted mainly by kidneys therefore contraindicated for pts with GFR < 35 mL/min |
| ca and bisphosphonates | IV zoledronate and pamidronate are indicated for hypercalcemia of malignancy; they can also be used as adjunct anti-ca tx esp. in prosta ca and MM. thought to inhibit other tumor proteins like Ras |
| FDA approved therapy for prevention & tx of osteoporosis | oral alendronate, risedronate, ibandronate& zoledronate |
| common adverse effects of bisphosphonates | esophageal irritation, hypocalcemia in pts with vitamin D deficiency, osteonecrosis of jaw when taking IV bisphosph. and on chemo, atypical hip fx and rarely impaired renal function |
| Raloxifene, a SERM approved by the FDA for tx of osteoporosis | interacts with estrogen receptors. absorbed well orally, hepatic metabolism, excretion in feces. significantly dec vertebral fx, may prevent breast ca in susceptible pts. adverse effects: hot flashes, DVT and leg cramps |
| calcitonin | works on native receptor to inhibit osteoclast resorption, comes SQ or intranasal, onset of action 2 hrs & lasts 6-8. excreted by kidney. indicated for osteoporosis, Paget dz of bone and hypercalcemia |
| denosumab (Prolia) | monoclonal Ab to RANKL, inhibits osteoclast activation, inc bone density, reduces risk of fx in osteoporotic women. reaches max levels in 10d and decline over 4-5 mo. adverse effects: hypocalcemia, jaw osteonecrosis, rash, infection and dec bone turnover |
| rPTH - teriparatide/Forteo indications | post-menopausal osteoporosis and even osteoporosis in men, either idiopathic or steroid-induced |
| adverse effects of teriparatide | shouldn't be given to those with open growth plates, those @ risk for osteosarcomas or Paget dz of bone or who've had skeletal radiation, unexplained inc alk phos levels. may cause kidney stones and uricemia |
| drugs of choice for CKD pts with mineral and bone disorders | doxercalciferol and paricalcitol |
| major adverse effects of vitamin D preparations | hypercalcemia, hypercalciuria and diminished renal function. may see extraskeletal calcifications when using calcitriol |
| targets of therapy in CKD | phosphorus retention, altered vitamin D metabolism and dysregulation of the CaSR |
| mechanism of action of PO4-binders | usually cationic polymeric compounds that bind PO4 in the intestinal lumen, inc fecal excretion and consequently lower the serum PO4 levels |
| sevelamer HCl and sevelamer carbonate | not absorbed by the GI tract, stay in the lumen. HCl may cause diarrhea with metabolic acidosis; giving the carbonate form prevents acidosis, but not diarrhea |
| lanthanum carbonate | rare-earth element with high avidity for PO4 and carboxyl groups. <0.002% absorbed in GI tract. no induced bone dz complication. |
| cheaper, effective alternatives to sevelamer class PO4 binders | calcium acetate and aluminum hydroxide. AlOH3 may cause aluminum-induced bone dz, dementia and EPO-resistant anemia |
| Cinacalcet and CKD | approved for pts with stage 5 CKD with GFR <15 mL/min or those with ESRD on dialysis. advantage of not rising serum Ca or PO4 while reducing serum PTH levels (want to keep it mildly elevated or they develop adynamic bone dz) |
| adverse effects of Cinacalcet | hypocalcemia, n/v. P450 interactions with erythromycin, beta blockers, TCAs, flecainie, ketoconazole, etc. |
Created by:
sirprakes
Popular Pharmacology sets