|Year : 2016 | Volume
| Issue : 1 | Page : 5-8
Academic heterogeneity: A tale of management of thyrotoxicosis across textbooks - A bibliometric review
Garima Bhutani1, Sanjay Kalra2, Puneet Dhamija3
1 Department of Pharmacology, BPS GMC For Women, Khanpur Kalan, Sonepat, India
2 Department of Endocrinology, Bharti Hospital and BRIDE, Karnal, Haryana, India
3 Department of Pharmacology, AIIMS, Rishikesh, Uttarakhand, India
|Date of Web Publication||5-Jan-2016|
Department of Pharmacology, BPS GMC For Women, Khanpur Kalan, Sonepat, Haryana
Source of Support: None, Conflict of Interest: None
Objectives: The aim of this communication is to assess whether the information about the management of thyrotoxicosis and thyrotoxic crisis as given in standard endocrinology, thyroidology and pharmacology textbooks is similar and concordant with each other. Methods: Three standard textbooks of endocrinology, one of diabetology and four of pharmacology were assessed for the published information regarding treatment of thyrotoxicosis and thyrotoxic crisis. Attention was given to the drugs used, their dose and prescribing frequency. Results: Various omissions and contradictions were found in the coverage of drugs used for thyrotoxicosis treatment in standard textbooks. Information about carbimazole, radio contrast media, cholestyramine, and lithium is missing in many of these texts. There were certain discrepancies in the doses of the drugs as is given in different textbooks. This is especially true in case of methimazole, propylthiouracil, and dexamethasone. Conclusions: This article stresses upon the need of homogeneity in different textbooks for providing adequate and accurate knowledge to physicians and students regarding frequency and dose of the drugs used in treatment of thyrotoxicosis and thyrotoxic crisis.
Keywords: Carbimazole, methimazole, posology, propylthiouracil, thyrotoxic crisis, thyrotoxicosis
|How to cite this article:|
Bhutani G, Kalra S, Dhamija P. Academic heterogeneity: A tale of management of thyrotoxicosis across textbooks - A bibliometric review. Thyroid Res Pract 2016;13:5-8
|How to cite this URL:|
Bhutani G, Kalra S, Dhamija P. Academic heterogeneity: A tale of management of thyrotoxicosis across textbooks - A bibliometric review. Thyroid Res Pract [serial online] 2016 [cited 2022 Jan 21];13:5-8. Available from: https://www.thetrp.net/text.asp?2016/13/1/5/168898
| Introduction|| |
Textbooks form an important source of information for physicians and medical students, both undergraduates and postgraduates. They sow the seeds of principles of management in the minds of readers which are updated from time to time. Readers expect complete, reliable and updated information from standard textbooks, which should be concordant with each other. This editorial assesses whether this expectation is met by leading pharmacology and endocrinology textbooks, in relation to the relatively “simple” pharmacotherapy of thyrotoxicosis.
Thyrotoxicosis which is a frequently encountered clinical condition due to a variety of underlying causes can be diagnosed with the triad of neck, eye and dermatological signs. Investigational modalities biochemical, immunological and imaging are used to identify the etiology for specific treatment, but management of thyrotoxicosis remain the same.
The treatment of thyrotoxicosis can be done using medical, surgical or radio therapeutic strategies. When compared to other endocrine conditions, such as diabetes, the pharmaco-therapeutic landscape of thyrotoxicosis appears relatively simple and homogenous. Just two classes of drugs (thionamides and thiouracil derivatives), including three molecules (carbimazimazole, methimazole and propylthiouracil [PTU]) are the main anti-thyroid drugs (ATDs). All three drugs are available, and are routinely used in India. Other drugs [Table 1] complete the list of drugs used in thyrotoxicosis, and in thyrotoxic crisis.
The purpose of this study is to assess, however, if the description of the management of thyrotoxicosis is similar across standard textbooks of endocrinology, thyroidology, and pharmacology.
| Materials and Methods|| |
Eight textbooks of pharmacology, thyroidology and endocrinology, which are followed by whole spectrum of medical practitioners in the country and abroad were analyzed for consistency and homogeneity of posology information regarding drugs used in the treatment of thyrotoxicosis. These textbooks included three leading endocrine texts (Endocrinology [De Groot LJ, Jameson JL, editors], Williams Textbook of endocrinology, ESI Manual of Clinical Endocrinology ), one dedicated thyroidology text (Werner and Ingbar's The Thyroid: A fundamental and clinical text), as well as four pharmacology books, Goodman and Gilman's the Pharmaceutical Basis of Therapeutics, Basic and Clinical Pharmacology (Katzung BG, Masters SB, Trevor AJ, editors), Essentials of Medical Pharmacology by KD Tripathi, Principles of Pharmacology by HL Sharma and KK Sharma. Some of these textbooks are American and some are Indian in origin. Relevant chapters from these books were read and information was compiled and captured in a master sheet.
| Results|| |
[Table 1] shows the comparison of information about thyrotoxicosis management available in different textbooks.
| Discussion|| |
Only William's Textbook of Endocrinology and two Indian textbooks of pharmacology mention carbimazole as one of the drugs for managing hyperthyroidism. ESI manual of clinical endocrinology does not mention starting dose of carbimazole and methimazole. PTU is mentioned by all the textbooks. De Groot teaches a starting dose of 20–40 mg/day of methimazole, and 200–400 mg/day of PTU. William prescribes a slighter lower initial dose of methimazole (20–30 mg), but the higher quantum of PTU (100–200 mg q 8 h). Werner opts for a slower start, with 20–30 mg/day of methimazole or 100 mg tds of PTU. The ESI Manual plays safe by not mentioning starting dose for these drugs. The frequency of titration is similar in all books though De Groot does confuse by suggesting titration at 4–6 weeks intervals, but thyroid function test at 1–3 months gaps. Daily maintenance dose of methimazole is mentioned as 5–10 mg by Williams and ESI Manual; and 10–15 mg by Werner. The maintenance dose of PTU is 50–100 mg 2–3 times a day as per Williams, and 100–200 mg/day according to ESI Manual. The other two endocrine textbooks omit this information. All pharmacology textbooks cover methimazole and PTU while only the Indian textbooks cover carbimazole. The doses are similar to those mentioned in clinical texts.
Lugol's iodine has largely been missed out by Williams, Werner and Ingbar, Katzung and HL Sharma whereas saturated solution of potassium iodide (SSKI) does not find mention in Williams, Werner and Ingbar and KD Tripathi. The advised doses of these drugs wherever found also vary widely. De Groot does not share the strengths of Lugol's solution and SSKI but suggests dose of 3–5 drops tds, and 1–3 drops tds, respectively. The ESI Manual provides complete information, however, Lugol iodine (160 mg/ml) in a dose of 5 drops per day, and SSKI (760 mg/ml) as/drop/day are prescribed. Goodman and Gilman mention both Lugol's iodine and SSKl, in both mg and drop strengths whereas Katzung and Tripathi propose measurement of SSKI as drops and mg respectively. Radioactive contrast media have been discussed by all textbooks except ESI Manual and Katzung. Surprisingly, none of the textbooks of pharmacology except the one by KD Tripathi mentions lithium as one of the drugs for managing hyperthyroidism while all textbooks of endocrinology mention it with doses. However, the prescribed doses have a lot of discrepancy among themselves. Three textbooks (De Groot, Katzung and KD Tripathi) do not mention the dose of perchlorates, whereas Williams and HL Sharma omit this molecule altogether. The prescribed doses are 400–600 mg/day, 500 mg bd and 750 mg/day according to Werner, ESI Manual and Goodman and Gilman respectively. De Groot and ESI Manual do not mention propanolol as one of the treatment of thyrotoxicosis while the doses mentioned by other texts are more or less consistent with each other. Williams is the only endocrine textbook to suggest a dose for dexamethasone (2 mg q 6 h), while Goodman and Gilman propose 0.5–1 mg, 24 times a day. The Indian pharmacology authors suggest use of hydrocortisone in thyroid storm, with KD Tripathi mentions use of hydrocortisone followed by oral prednisolone. Cholestyramine, however, is skipped by three foreign endocrine books surveyed, and mentioned only in the ESI Manual (dose: 4 g 6 h). None of the pharmacology authors include the dose of this molecule, either. On the other hand, diltiazem continues to be listed by all pharmacology books, although it is not mentioned in clinical books.
The possible reasons for the heterogeneity across textbooks include approval status of drug in the region of authors (e.g., carbimazole is not approved in US), clinician's versus pharmacologist's perspective of managing diseases (e.g. Lithium for management of hyperthyroidism), the readers targeted by the book (e.g., textbooks of pharmacology mention maximum number of drugs), the references available at the time of publication of book, the review process and last but not the least, the contributor of the chapter.
| Conclusions|| |
This discussion highlights the various omissions and commissions related to textbook coverage of thyrotoxicosis management, which serve to confuse the students and clinicians. While many discrepancies pointed above are minor, others are significant. These include the starting and maintenance doses of methimazole and PTU, as well as the lack of information related to carbimazole. While Williams and Werner do mention the relative equivalent doses of the two drugs (10 mg carbimazole is equivalent to 6 mg methimazole), de Groot and ESI Manual do not give this conversion factor. For the average Indian physician, used to titrating carbimazole doses rather than methimazole requirements, this silence is confusing.
While the art and science of ATD dose titration is highly person-centric (and physician-specific), it would be helpful if all standard textbooks were to keep their information uniform, and concordant, with approved prescribing information. Although clinical practice is not only guided by text-books and it is rare to find classical cases, homogeneity across books is required for the right guidance. Additionally, onus of providing the maximum information lies on text-books of pharmacology than medicine. There should be interdisciplinary communication between pharmacology, endocrinology, and thyroidology, to ensure that medical students receive and assimilate accurate knowledge.
| References|| |
Marino M, Chiovato L, Pinchera A. Graves' disease. In: DeGroot LJ, Jameson JL, editors. Endocrinology. 5th
ed. Philadelphia: Elsevier Saunders; 2006. p. 1995-2028.
Mandel SJ, Larsen PR, Davies TF. Thyrotoxicosis. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, editors. Williams Textbook of Endocrinology. 12th
ed. Philadelphia: Elsevier Saunder; 2011. p. 362-405.
Sahay RK, Bantwal G. Thyrotoxicosis. In: Bajaj S, editor. ESI Manual of Clinical Endocrinology. 2nd
ed. New Delhi: Jaypee Brothers Medical Publishers; 2015. p. 319-26.
Cooper DS. Treatment of thyrotoxicosis. In: Braverman LE, Cooper DS, editors. Werner and Ingbar's the Thyroid: A Fundamental and Clinical Text. 10th
ed. New Delhi: Wolters Kluwer; 2013. p. 492-515.
Brent GA, Koenig RJ. Thyroid and anti thyroid drugs. In: Brunton LL, Chabner BA, Knollmann BC, editors. Goodman and Gilman's the Pharmaceutical Basis of Therapeutics. 12th
ed. New York: Tata McGraw Hill; 2011. p. 1129-62.
Dong BJ, Greenspan FS. Thyroid and anti thyroid drugs. In: Katzung BG, Masters SB, Trevor AJ, editors. Basic and Clinical Pharmacology. 12th
ed. New York: Tata McGraw Hill; 2012. p. 681-96.
Tripathi KD. Thyroid hormones and thyroid inhibitors. In: Essentials of Medical Pharmacology. 7th
ed. New Delhi: Jaypee Brothers Medical Publishers; 2013. p. 245-57.
Sharma HL, Sharma KK. Thyroid and anti thyroid drugs. In: Principles of Pharmacology. 2nd
ed. Hyderabad: Paras Medical Publisher; 2010. p. 606-16.