Thyroxine Essay
Q5. Finding information for the follow medications-
1.Thyroxine
2. Alendronate
3. Ginkgo Biloba
Thyroxine
Introduction- Thyroxine tablets are important in managing hypothyroidism, but treatment may be sub-optimal if they are used incorrectly. The tablets have pharmaceutical properties, which can impair the patients management. Discussing the correct use and storage of the tablets is an important part of prescribing thyroxine.
Availability
Synthetic preparations of thyroxine contain the laevo isomer of thyroxine, usually as the sodium salt. There are two brands of thyroxine available in Australia, each as 50 microgram, 100 microgram and 200 microgram tablets (pack size 200) with five repeats on the Pharmaceutical Benefits Scheme. …show more content…
Parenteral preparations of thyroid hormone have little use in Australia, outside of specialist centres.
The two Australian brands are marketed by Sigma and one of its subsidiaries. They are identical products so patients can swap them safely, but this assumption should not be extended to overseas brands.
Stability
Thyroxine is stable in dry air, but unstable in the presence of light, heat and humidity. In some cases overseas, thyroxine tablets have been unstable even at room temperature, and storage temperatures of 8°C to 15°C were required to maintain potency. In the USA, the Food and Drug Administration has determined that stability and potency problems with oral thyroxine preparations could potentially have adverse effects on health. It is therefore very important that thyroxine tablets should be kept in their original container and stored out of sunlight in a cool dry place.1
The expiry date for Australian manufactured thyroxine tablets is one year from the date of manufacture.
Absorption
Thyroxine is variably absorbed from the gut following oral administration. It has a bioavailability of 40–80%. Absorption may decrease with age.
Administration
Patients should be instructed to take thyroxine 30–60 minutes before breakfast in order to maximize absorption. If this is too difficult or threatens compliance, the patient may try taking the thyroxine last thing at night on an empty stomach. Patients who still decide to take their tablets with, rather than before, breakfast need to do this consistently, to avoid fluctuating thyroxine concentrations. Depending on the fiber and milk content of the meal, taking thyroxine with food may require a larger dose to maintain euthyroidism, because of the decreased bioavailability.
Onset and duration of action
The half-life of thyroxine in euthyroidism is 6–7 days. This is reduced to 3–4 days in hyperthyroidism and prolonged to 9–10 days in hypothyroidism. Thyroxine has a full therapeutic effect 3–4 weeks after starting treatment and will continue to have a therapeutic action for 1–3 weeks after treatment stops. In view of the long half-life, dose changes should only be made every 3–4 weeks. Despite undergoing both hepatic and renal clearance, there is no evidence that dose adjustment is required for patients with liver or kidney disease.1,2
Monitoring
The dosage is adjusted according to thyroxine and thyroid stimulating hormone plasma concentrations, which should always be interpreted in conjunction with each other and the patients condition.4 Monitoring is suggested at six-weekly intervals when starting therapy until the patient has stabilized, then six monthly thereafter, or earlier if symptoms suggestive of hyper-or hypothyroidism occur.
Drug interactions
Most drug interactions are seen during shifts to and from the euthyroid state and rarely have any clinical significance during periods of thyroid stability. The hyperthyroid state increases clearance of some hepatically cleared drugs, notably propranolol, metoprolol and theophylline. Antacids, iron salts, calcium carbonate (milk), sucralfate, cholestyramine and soy-based formulas reduce the absorption of thyroxine.
Conclusion
There are significant stability, absorption and drug interaction issues surrounding the use of thyroxine. It is essential that prescribers and pharmacists convey this information to patients in order that therapeutic efficacy may be maximized.
Alendronate
Alendronate is used to treat and prevent osteoporosis (a condition in which the bones become thin and weak and break easily) in women who have undergone menopause ( ' 'change of life, ' ' end of menstrual periods) and to treat osteoporosis in men. Alendronate is also used to treat osteoporosis in men and women who are taking corticosteroids (a type of medication that may cause osteoporosis in some patients). Alendronate is also used to treat Paget 's disease of bone (a condition in which the bones are soft and weak and may be deformed, painful, or easily broken). Alendronate is in a class of medications called bisphosphonates. It works by preventing bone breakdown and increasing bone density (thickness).
Ginkgo Biloba
What is it?
Ginkgo is an herb. The leaves are generally used to make “extracts” that are used as medicine. However, a few medicines are made from the seed, but these are not well studied.
Ginkgo is often used for memory disorders including Alzheimer’s disease.
It is also used for conditions that seem to be due to reduced blood flow in the brain, especially in older people. These conditions include memory loss, headache, ringing in the ears, vertigo, difficulty concentrating, mood disturbances, and hearing disorders. Some people use it for other problems related to poor blood flow in the body, including leg pain when walking (claudication), and Raynaud’s syndrome (a painful response to cold, especially in the fingers and toes).
Ginkgo leaf is also used for thinking disorders related to Lyme disease and depression.
Some people use ginkgo to treat sexual performance problems. It is sometimes used to reverse the sexual performance problems that can accompany taking certain antidepressants called SSRIs.
Ginkgo been tried for eye problems including glaucoma, diabetic eye disease, and age-related macular degeneration (AMD).
The list of other uses of ginkgo is very long. This may be because this herb has been around for so long. Ginkgo biloba is one of the longest living tree species in the world. Ginkgo trees can live as long as a thousand years. Using ginkgo for asthma and bronchitis was described in 2600
BC.
In manufacturing, ginkgo leaf extract is used in cosmetics. In foods, roasted ginkgo seed, which has the pulp removed, is an edible delicacy in Japan and China. Remember, though, the whole seed is LIKELY UNSAFE to eat.
Ginkgo interacts with many medicines. Before taking it, talk with your healthcare provider if you take any medications.
References
1. AHFS drug handbook. 2nd ed. Bethesda (MD): American Society of Health-System Pharmacists, Lippincott Williams & Wilkins; 2003.
2. Thomas J, editor. Australian Prescription Products Guide 2003. 32nd ed. Hawthorn: Australian Pharmaceutical Publishing Company Limited; 2003.
3. Grebe SK, Cooke RR, Ford HC, Fagerstrom JN, Cordwell DP, Lever NA, et al. Treatment of hypothyroidism with once weekly thyroxine. J Clin Endocrinol Metab 1997;82:870-5.
http://www.nlm.nih.gov/medlineplus/druginfo/natural/333.html
1.Thyroxine
2. Alendronate
3. Ginkgo Biloba
Thyroxine
Introduction- Thyroxine tablets are important in managing hypothyroidism, but treatment may be sub-optimal if they are used incorrectly. The tablets have pharmaceutical properties, which can impair the patients management. Discussing the correct use and storage of the tablets is an important part of prescribing thyroxine.
Availability
Synthetic preparations of thyroxine contain the laevo isomer of thyroxine, usually as the sodium salt. There are two brands of thyroxine available in Australia, each as 50 microgram, 100 microgram and 200 microgram tablets (pack size 200) with five repeats on the Pharmaceutical Benefits Scheme. …show more content…
Parenteral preparations of thyroid hormone have little use in Australia, outside of specialist centres.
The two Australian brands are marketed by Sigma and one of its subsidiaries. They are identical products so patients can swap them safely, but this assumption should not be extended to overseas brands.
Stability
Thyroxine is stable in dry air, but unstable in the presence of light, heat and humidity. In some cases overseas, thyroxine tablets have been unstable even at room temperature, and storage temperatures of 8°C to 15°C were required to maintain potency. In the USA, the Food and Drug Administration has determined that stability and potency problems with oral thyroxine preparations could potentially have adverse effects on health. It is therefore very important that thyroxine tablets should be kept in their original container and stored out of sunlight in a cool dry place.1
The expiry date for Australian manufactured thyroxine tablets is one year from the date of manufacture.
Absorption
Thyroxine is variably absorbed from the gut following oral administration. It has a bioavailability of 40–80%. Absorption may decrease with age.
Administration
Patients should be instructed to take thyroxine 30–60 minutes before breakfast in order to maximize absorption. If this is too difficult or threatens compliance, the patient may try taking the thyroxine last thing at night on an empty stomach. Patients who still decide to take their tablets with, rather than before, breakfast need to do this consistently, to avoid fluctuating thyroxine concentrations. Depending on the fiber and milk content of the meal, taking thyroxine with food may require a larger dose to maintain euthyroidism, because of the decreased bioavailability.
Onset and duration of action
The half-life of thyroxine in euthyroidism is 6–7 days. This is reduced to 3–4 days in hyperthyroidism and prolonged to 9–10 days in hypothyroidism. Thyroxine has a full therapeutic effect 3–4 weeks after starting treatment and will continue to have a therapeutic action for 1–3 weeks after treatment stops. In view of the long half-life, dose changes should only be made every 3–4 weeks. Despite undergoing both hepatic and renal clearance, there is no evidence that dose adjustment is required for patients with liver or kidney disease.1,2
Monitoring
The dosage is adjusted according to thyroxine and thyroid stimulating hormone plasma concentrations, which should always be interpreted in conjunction with each other and the patients condition.4 Monitoring is suggested at six-weekly intervals when starting therapy until the patient has stabilized, then six monthly thereafter, or earlier if symptoms suggestive of hyper-or hypothyroidism occur.
Drug interactions
Most drug interactions are seen during shifts to and from the euthyroid state and rarely have any clinical significance during periods of thyroid stability. The hyperthyroid state increases clearance of some hepatically cleared drugs, notably propranolol, metoprolol and theophylline. Antacids, iron salts, calcium carbonate (milk), sucralfate, cholestyramine and soy-based formulas reduce the absorption of thyroxine.
Conclusion
There are significant stability, absorption and drug interaction issues surrounding the use of thyroxine. It is essential that prescribers and pharmacists convey this information to patients in order that therapeutic efficacy may be maximized.
Alendronate
Alendronate is used to treat and prevent osteoporosis (a condition in which the bones become thin and weak and break easily) in women who have undergone menopause ( ' 'change of life, ' ' end of menstrual periods) and to treat osteoporosis in men. Alendronate is also used to treat osteoporosis in men and women who are taking corticosteroids (a type of medication that may cause osteoporosis in some patients). Alendronate is also used to treat Paget 's disease of bone (a condition in which the bones are soft and weak and may be deformed, painful, or easily broken). Alendronate is in a class of medications called bisphosphonates. It works by preventing bone breakdown and increasing bone density (thickness).
Ginkgo Biloba
What is it?
Ginkgo is an herb. The leaves are generally used to make “extracts” that are used as medicine. However, a few medicines are made from the seed, but these are not well studied.
Ginkgo is often used for memory disorders including Alzheimer’s disease.
It is also used for conditions that seem to be due to reduced blood flow in the brain, especially in older people. These conditions include memory loss, headache, ringing in the ears, vertigo, difficulty concentrating, mood disturbances, and hearing disorders. Some people use it for other problems related to poor blood flow in the body, including leg pain when walking (claudication), and Raynaud’s syndrome (a painful response to cold, especially in the fingers and toes).
Ginkgo leaf is also used for thinking disorders related to Lyme disease and depression.
Some people use ginkgo to treat sexual performance problems. It is sometimes used to reverse the sexual performance problems that can accompany taking certain antidepressants called SSRIs.
Ginkgo been tried for eye problems including glaucoma, diabetic eye disease, and age-related macular degeneration (AMD).
The list of other uses of ginkgo is very long. This may be because this herb has been around for so long. Ginkgo biloba is one of the longest living tree species in the world. Ginkgo trees can live as long as a thousand years. Using ginkgo for asthma and bronchitis was described in 2600
BC.
In manufacturing, ginkgo leaf extract is used in cosmetics. In foods, roasted ginkgo seed, which has the pulp removed, is an edible delicacy in Japan and China. Remember, though, the whole seed is LIKELY UNSAFE to eat.
Ginkgo interacts with many medicines. Before taking it, talk with your healthcare provider if you take any medications.
References
1. AHFS drug handbook. 2nd ed. Bethesda (MD): American Society of Health-System Pharmacists, Lippincott Williams & Wilkins; 2003.
2. Thomas J, editor. Australian Prescription Products Guide 2003. 32nd ed. Hawthorn: Australian Pharmaceutical Publishing Company Limited; 2003.
3. Grebe SK, Cooke RR, Ford HC, Fagerstrom JN, Cordwell DP, Lever NA, et al. Treatment of hypothyroidism with once weekly thyroxine. J Clin Endocrinol Metab 1997;82:870-5.
http://www.nlm.nih.gov/medlineplus/druginfo/natural/333.html