Monday, July 27, 2020

Coal Tar



No
Year
Title
Finding(s)
Reference(s)
1
2020
Bluebook / FUKKM [online]

Generic Name
Cate-gory
Indications
Dosage
Coal Tar 1-9% Ointment
B
Dandruff, seborrhoeic dermatitis, atopic dermatitis, eczema and psoriasis. Used as a mild astringent for the skin, as a soothing and protective application in eczema and as a protective to slight excoriation
Apply sparingly to the affected area 1-3 times daily starting with low strength preparations
Coal Tar 20% Solution
B
Dandruff, seborrhoeic dermatitis, atopic dermatitis, eczema and psoriasis
Use 100 ml in a bath


-
2
2019
Subpart H - Drug Products for the Control of Dandruff, Seborrheic Dermatitis, and Psoriasis     Sec. 358.710 Active ingredients for the control of dandruff, seborrheic dermatitis, or psoriasis

·          Active ingredients for the control of seborrheic dermatitisand psoriasis. Coal tar, 0.5 to 5 percent. When a coal tar solution, derivative, or fraction is used as the source of the coal tar, the labelling shall specify the identity and concentration of the coal tar source used and the concentration of the coal tar presentin the final productà OTC Products

CFR - Code of Federal Regulations Title 21. (n.d.). www.accessdata.fda.gov. Retrieved July 21, 2020, from https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=358.710&SearchTerm=coal%20tar
3
2016
Management of scalp psoriasis: current perspectives

i) Shampoo: There are some studies available that support the use of coal tar shampoo, containing 2% – 10% coal tar solution, in scalp psoriasis; however, no double-blind studies are available to support this practice and many patients do not find tar shampoos cosmetically acceptable. Salicylic acid shampoo, due to its keratolyticeffect, has also been used to enhance the penetration of other topical medications including corticosteroids, and has been recommended by The National Psoriasis Foundation as a first-line therapy. However, a recent Cochrane review of clinical trials on scalp psoriasis found no evidence to support the first-line use of a tar-based shampoo, with or without a keratolytic such as salicylic acid.

ii) Topical: Coal tar has been used as a treatment for psoriasis for several decades due to its anti-proliferative and anti-inflammatory actions, and its potent anti-pruritic properties. Although crude coal tar is the most effective tar available for the treatment of psoriasis, the application of crude coal tar to the scalp presents a challenge. As such, coal tar solution or liquor carbonisdetergens 5% – 20% is frequently recommended, formulated as a lotion, or added to a corticosteroid preparation. Of note, the use of coal tar has largely fallen out of favor to newer topical medications. Tar’s malodour, adverse effects (hair staining and drying), and carcinogenicity limit its use, although newer studies challenge these findings. The use of coal tar in cosmetic preparations has been banned in Canada and the European Union over concerns regarding carcinogenicity.

Blakely, K., & Gooderham, M. (2016, March 29). Management of scalp psoriasis: current perspectives. Psoriasis: Targets and Therapy. https://www.dovepress.com/management-of-scalp-psoriasis-current-perspectives-peer-reviewed-fulltext-article-PTT
4
2018
Topical Preparations Counselling Guide for Pharmacist (1st edition)
Coal tar solution 20%
• 1 cap (15 mL) added to 10L of water in a pail
• Soak diluted solution for 20 minutes
• Do not rinse again with tap water

-
5
-
Coal tar
Topical/Cutaneous
Dandruff, Seborrheic dermatitis
Adult: As 1%, 2.5% shampoo: Massage into we scalp. Leave for several minutes then rinse thoroughly. May use up to twice weekly.
Child: Same as adult dose.
Elderly: Same as adult dose.


Topical/Cutaneous
Psoriasis of skin and scalp
Adult: As a 5% emulsion: Apply a thin layer 2-3 times daily to affected areas, massage gently and leave to dry.
Child: >12 years Same as adult dose.
Elderly: Same as adult dose.


6
-
Coal tar: Drug information
(Dosing for Adult)
Seborrhea, dermatitis: Topical:

Skin: Apply to the affected area 1 to 4 times/day; decrease frequency to 2 to 3 times/week once condition has been controlled

Bath: Add appropriate amount to bath water, for adults usually 60-90 mL of a 5% to 20% solution or 15 to 25 mL of 30% lotion; soak 5 to 20 minutes, then pat dry; use once daily to every 3 days

Dandruff: Shampoo: Rub shampoo onto wet hair and scalp, rinse thoroughly; repeat; leave on 5 minutes; rinse thoroughly; apply twice weekly for the first 2 weeks then once weekly or more often if needed

Psoriasis: Topical:

Scalp psoriasis: Tar oil bath or coal tar solution may be painted sparingly to the lesions 3 to 12 hours before each shampoo

Psoriasis of the body, arms, legs: Apply at bedtime; if thick scales are present, use product with salicylic acid and apply several times during the day


UpToDate
7
1974
British Medical Journal
Tar bath: 120 ml coal tar solution B.P. in a 20-gallon bath

**Coal tar solution BP = Coal tar solution 20%
***20 gallon 76L
Stankler, P. (1974). BRITISH MEDICAL JOURNAL Today’s Treatment Diseases of the Skin. https://www.bmj.com/content/bmj/1/5896/27.full.pdf
8
-
Coal tar and carcinogenicity

Coal tar products containing coal tar above a concentration of 5% are listed by the World Health Organisation as carcinogenic.

However, reviews of the literature have been unable to uncover evidence of increased risk of cancer in those treated with medical formulations of coal tar. Studies of patients receiving long term treatment with coal tar have also not found evidence of an increased risk of cancer. A recent in depth analysis of patients receiving tar based anti-psoriasis treatment compared with alternative medications found no evidence of an increased risk of skin cancer associated with tar.

From latest studies, coal tar is found to be carcinogenic in animals, but in humans, there are no convincing data proving carcinogenicity, and epidemiologic studies fail to show increased risk of skin cancer in patients who use coal tar.

Section 13.4 Dermatological medicines (topical) -Medicines affecting skin differentiation and proliferation Coal tar. (n.d.). Retrieved July 21, 2020, from https://www.who.int/selection_medicines/committees/expert/19/applications/Coaltar_13_4_A_R.pdf


Summary: Comparison of Concentrations


Reference
Shampoo
Bath
Topical
1
Bluebook/FUKKM Online (2020)

Add 100ml of 20% into a bath
1-9% ointment
2
Management of scalp psoriasis: current perspectives (2016)
2-10%

5-20% (as a lotion / added to a corticosteroid preparation.
3
Topical Preparations Counselling Guide for Pharmacist (1st edition) 2018

15 ml of 20% à 10 L water

4
MIMS online: Coal tar
1-2.5%

5% for psoriasis of skin and scalp
Cream 6% available
5
UptoDate: Drug Information: Coal Tar

60-90 mL of 20% solution to appropriate amount of bath water

6
British Medical Journal 1974

120 ml of 20% à 76 L water

7
Micromedex coal tar products
0.5-5%

2-3% (except Oxipor VHC: lotion 25%)
8
UptoDate: coal tar products
0.5-10%

2-10%


All accessed on 22 July 2020 [Prepared by Noratikah ; Edited by JCK Ho]

Friday, July 24, 2020

Statins : Administration Time & Equivalence

  • Statins lower cholesterol levels through inhibition of HMG-CoA reductase.
  • Although all statins go through hepatic metabolism, the elimination half-lives vary in length.  Simvastatin, fluvastatin, and lovastatin have a short elimination half-life compared to other drugs within the class.  Agents with significantly shorter elimination half-lives require bedtime dosing to maximize efficacy - allowing the greatest statin concentration to be present while endogenous cholesterol synthesis is the highest.  Alternatively, the longer half-lives of rosuvastatin, atorvastatin, pitavastatin, and pravastatin allow these agents to maintain a therapeutic drug concentration over a 24-hour period and allow alternate administration times.
  • LDL-C and TC lowering was significantly greater in the evening dose than in the morning dose in case of short-acting statins. Besides slight but significant effect on LDL-C, the efficacy of long-acting statins was equivalent for both regimens. Therefore, long-acting statins should be given at a time that will best aid compliance. Short-acting statins should be given in the evening.
  • The half-life of atorvastatin is about 14 hours, while its active metabolites have a half-life of about 20 to 30 hours. Agents with longer half-lives allow for greater flexibility in administration time, which may improve compliance and ultimately result in greater LDL-C reduction and ability to achieve cholesterol goals.
  • Simvastatin is a prodrug activated by first-pass hepatic metabolism to a hydroxyacid metabolite, which has a half-life of 1–2 hours.





Statin
Half-Life
Suggested Time of Administration
Lovastatin (Mevacor)
1.1 – 1.7 hours
Night
Simvastatin (Zocor)
3 hours
Night
Fluvastatin (Lescol)
IR: <3 hours
ER: 9 hours
Night
Pitavastatin (Livalo)
12 hours
Anytime
Atorvastatin (Lipitor)
Parent Drug: 14 hours
Metabolites: 20 – 30 hours
Anytime
Rosuvastatin (Crestor)
19 hours
Anytime
Pravastatin (Pravachol)
77 hours
Anytime

Table: Half-life and suggested administration



Statin
Dosage
Low-intensity
(LDL-C reduction <30%)
Moderate-intensity
(LDL-C reduction 30% to <50%)
High-intensity
(LDL-C reduction >50%)
Atorvastatin
NA
10 to 20 mg
40 to 80 mg
Fluvastatin
20 to 40 mg
40 mg 2×/day;
XL 80 mg
NA
Lovastatin
20 mg
40 mg
NA
Pitavastatin
1 mg
2 to 4 mg
NA
Pravastatin
10 to 20 mg
40 to 80 mg
NA
Rosuvastatin
NA
5 to 10 mg
20 to 40 mg
Simvastatin
10 mg
20 to 40 mg
NA

Table: Statin Dosing and ACC/AHA Classification of Intensity, 2013
References:
1.        Awad, K., Serban, M.-C., Penson, P., Mikhailidis, D. P., Toth, P. P., Jones, S. R., Rizzo, M., Howard, G., Lip, G. Y. H., &Banach, M. (2017). Effects of morning vs evening statin administration on lipid profile: A systematic review and meta-analysis. Journal of Clinical Lipidology11(4), 972–985.e9. https://doi.org/10.1016/j.jacl.2017.06.001
2.        Chou R, Dana T, Blazina I, et al. Statin Use for the Prevention of Cardiovascular Disease in Adults: A Systematic Review for the U.S. Preventive Services Task Force [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2016 Nov. (Evidence Syntheses, No. 139.) Table 1, Statin Dosing and ACC/AHA Classification of Intensity. Available from: https://www.ncbi.nlm.nih.gov/books/NBK396417/table/ch1.t1/
3.        Plakogiannis, R., & Cohen, H. (2007). Optimal low-density lipoprotein cholesterol lowering--morning versus evening statin administration. The Annals of pharmacotherapy41(1), 106–110. https://doi.org/10.1345/aph.1G659
4.        Which Statin Is the Best Choice for Which Patient? (2014). American Family Physician65(6), 1211. https://www.aafp.org/afp/2002/0315/p1211.html
5.        (n.d.). Statin Dose Intensity and Equivalency Chart [Review of Statin Dose Intensity and Equivalency Chart]. UMHS Lipid Therapy Guideline. http://www.mqic.org/pdf/UMHS_Statin_Dose_Intensity_and_Equivalency_Chart.pdf


All information accessed on 17 July 2020 [Prepared by Noratikah ; Edited by JCK Ho]