North American cost analysis of brand name versus generic drugs for the treatment of glaucoma

Figures & data

Table 1 Annual cost data from Mckesson Canada Inc. of glaucoma medications by class of drug

Brand name drug	Cost ($/Pk)	Volume/bottle (mL)	Drops/mL	Drops/bottle	Dose/day (OU)	Theor. days/bottle	Bottles/year	Cost/year ($)	Waste adjustment	Pharm. adj. costs/year ($)
a) Combination drugs
Cosopt	62.95	10.9	25.9	282.31	4	70.58	5.17	354.85	2.14	758.93
Average cost								354.85		758.93
Avg annual cost to OHIP								391.64		828.04
b) Carbonic anhydrase inhibitors (CAIs)
Trusopt	20.16	5.4	25.7	138.78	5	27.76	13.15	53.02	1.65	37.06
Azopt	17.31	5	24.6	123	5	24.60	14.84	51.37	1.65	31.82
Average cost								52.19		34.44
Avg annual cost to OHIP								64.77		45.59
c) α-agonists covered by OHIP
Alphagan P	12.42	5.4	21.1	113.94	4	28.49	12.81	31.83	0.89	28.33
Alphagan	17.74	5.4	21.1	113.94	4	28.49	12.81	45.46		32.61
Average cost								38.65		30.47
Avg annual cost to OHIP								50.14		41.31
d) Prostaglandin analogs
Travatan	58.14	5.4	34	183.6	2	91.80	3.98	249.66	2.35	587.66
Xalatan	29.07	3.05	32	97.6	2	48.80	7.48	265.26	1.25	331.92
Lumigan RC	34.88	3.3	37.4	123.42	2	61.71	5.91	226.94	1.55	352.63
Average cost								202.66		350.20
Avg annual cost to OHIP								227.27		386.62
e) β-blockers
Timolol	29.73	10.9	32.6	355.34	4	88.84	4.11	12.22	1.65	27.32
Timolol	36.99	10.9	32.6	355.34	4	88.84	4.11	15.20	1.65	34.00
Timoptic-XE	19.91	6	26.1	156.6	2	78.30	4.66	18.56	1.54	28.50
Timoptic-XE	23.83	6	26.1	156.6	2	78.30	4.66	22.22	1.54	34.11
Betoptic S	23.96	5.2	29.4	152.88	4	38.22	9.55	45.76	0.96	44.04
Betagan	17.69	10.2	21.1	215.22	4	53.81	6.78	12.00	1.35	16.26
Average cost								20.99		30.70
Avg annual cost to OHIP								31.07		41.56
f) Cholinergic agonists
Pilopine Hs gel	13.43	5	25	125	4	31.25	11.68	31.37	1.65	24.69
Isopto carpine 1%	3.25	5	25	125	4	31.25	11.68	7.59	1.65	5.97
Isopto carpine 2%	3.75	5	25	125	4	31.25	11.68	8.76	1.65	6.89
Isopto carpine 4%	4.24	5	25	125	4	31.25	11.68	9.90	1.65	7.79
Average cost								14.41		11.34
Avg annual cost to OHIP								23.96		20.64

Table 2 Utility rates for various medications class

Therapy	No. of prescriptions (%)
	Combination drugs	CAIs	α-Agonists	Prostaglandin	β-blockers	Cholinergic agonists
Mono-drug therapy	38 (9)	2 (0)	13 (3)	221 (54)	126 (31)	7 (2)
Bi-drug therapy	84 (18)	27 (6)	39 (8)	203 (42)	114 (24)	16 (3)
Tri-drug therapy	23 (12)	22 (12)	44 (24)	57 (31)	27 (15)	14 (7)
Total occurrences of drug	145 (14)	51 (5)	96 (9)	481 (45)	267 (25)	37 (2)

Notes: Adapted with permission from Lee R, Hutnik CML. Projected cost comparison of selective laser trabeculoplasty versus glaucoma medication in the Ontario Health Insurance Plan. Can J Ophthalmol. 2006;41(4):449–456. doi:10.1016/S0008-4182(06)80006-2A.¹⁹ Adapted from Iordanous Y, Kent JS, Hutnik CML, Malvankar-Mehta MS. Projected cost comparison of trabectome, iStent, and endoscopic cyclophotocoagulation versus glaucoma medication in the Ontario Health Insurance Plan. J Glaucoma. 2014;23(2):e112-e118. doi: 10.1097/IJG.0b013e31829d9bc7. Copyright © 2014, © 2014 by Lippincott Williams.²²

Table 3 Frequency of mono-, bi-, and tri-drug therapies for treatment of glaucoma in Ontario

	No. of patients (%)
Mono-drug therapy	407 (57.6)
Bi-drug therapy	239 (33.8)
Tri-drug therapy	61 (8.6)
Total number of patients	707 (100)

Note: Adapted with permission from Lee R, Hutnik CML. Projected cost comparison of selective laser trabeculoplastyversus glaucoma medication in the Ontario Health InsurancePlan. Can J Ophthalmol. 2006;41(4):449–456. doi:10.1016/S0008-4182(06)80006-2A.¹⁹ Adapted from Iordanous Y, Kent JS, Hutnik CM, Malvankar-Mehta MS. Projected cost comparison of trabectome, iStent, and endoscopic cyclophotocoagulation versus glaucoma medication in the Ontario Health Insurance Plan. J Glaucoma. 2014;23(2):e112-8. doi: 10.1097/IJG.0b013e31829d9bc7. Copyright © 2014, © 2014 by Lippincott Williams. ²²

Figure 1 Average annual OHIP cost by medication class.

Table 4 Annual cost data from Ontario Drug Benefit (ODB) Formulary of glaucoma medications by class of drug

Generic drug	Daily cost ($/mL, Pk)	Volume/bottle (mL)	Drops/mL	Drops/bottle	Dose/day OU	Theor. days/bottle	Bottles/year	Cost/year ($)	Waste adjustment	Pharm. adj. costs/year ($)
a) Combination drugs
Dorzolamide HCL-timolol (0.5%) (10 mL)	56.82	10.9	25.9	282.31	4	70.58	5.17	320.30	2.14	685.03
Average cost								320.30		685.03
Avg annual cost to OHIP								353.90		748.23
b) Carbonic anhydrase inhibitors (CAIs)
Dorzolamide HCL (2%) (5 mL)	3.79	5.4	25.7	138.78	5	27.76	13.15	53.88	1.65	37.66
Brinzolamide (1%)(5 mL)	3.28	5	24.6	123	5	24.60	14.84	48.73	1.65	30.19
Average cost								51.31		33.92
Avg annual cost to OHIP								58.01		45.04
c) α-agonists covered by OHIP
Brimonidine (0.15%)(5 mL)	2.02	5.4	21.1	113.94	4	28.49	12.81	27.97	0.89	24.90
Brimonidine (0.2%)(5 mL)	1.58	5.4	21.1	113.94	4	28.49	12.81	21.92		15.72
Average cost								24.95		20.31
Avg annual cost to OHIP								29.01		30.34
d) Prostaglandin analogs
Travoprost 0.004% (5 mL Pk)	10.82	5.4	34	183.6	2	91.80	3.98	46.45	2.35	109.32
Latanoprost 0.005% (2.5 mL Pk)	27.38	3.05	32	97.6	2	48.80	7.48	74.80	1.25	93.59
Bimatoprost 0.03% (3 mL)	10.81	3.3	37.4	123.42	2	61.71	5.91	70.33	1.87	131.52
Bimatoprost 0.01% (3 mL Pk)	32.43	3.3	37.4	123.42	2	61.71	5.91	211.00	1.55	327.86
Average cost								144.40		220.33
Avg annual cost to OHIP								160.41		246.36
e) β-blockers
Timolol (0.25%) (10 mL)	0.97	10.9	32.6	355.34	4	88.84	4.11	4.33	1.65	9.70
Timolol (0.50%) (10 mL)	1.70	10.9	32.6	355.34	4	88.84	4.11	7.61	1.65	17.03
Timoptic - XE (0.25%) (5 mL)	2.92	6	26.1	156.6	2	78.30	4.66	16.35	1.54	25.10
Timoptic - XE (0.5%) (5 mL)	3.11	6	26.1	156.6	2	78.30	4.66	17.40	1.54	26.72
Betaxolol (0.25%) (5 mL)	2.27	5.2	29.4	152.88	4	38.22	9.55	22.57	0.96	21.72
Levobunolol (0.5%) (10 mL)	1.69	10.2	21.1	215.22	4	53.81	6.78	11.67	1.35	15.81
Average cost								13.32		19.35
Avg annual cost to OHIP								16.23		29.29
f) Cholinergic agonists
Pilocarpine HCL (4%) gel (5 mL)	2.55	5	25	125	4	31.25	11.68	29.76	1.65	23.42
Pilocarpine HCL (1%) (5 mL)	0.21	5	25	125	4	31.25	11.68	2.44	1.65	1.92
Pilocarpine HCL (2%)(5 mL)	0.24	5	25	125	4	31.25	11.68	2.81	1.65	2.21
Pilocarpine HCL (4%) (5 mL)	0.27	5	25	125	4	31.25	11.68	3.18	1.65	2.50
Average cost								9.55		7.51
Avg annual cost to OHIP								12.07		16.516

Figure 2 Difference between branded and generic medications for mono-, bi-, and tri-drug therapy for over 6 years.

Figure 3 Percentage difference between branded and generic medications for mono-, bi-, and tri-drug therapy for over 6 years.

Figure 4 Difference between branded and generic medications for various medication classes over 6 years.

Figure 5 Percentage difference between branded and generic medications for various medication classes for over 6 years.

Lee R, Hutnik CML. Projected cost comparison of selective laser trabeculoplasty versus glaucoma medication in the Ontario Health Insurance Plan. Can J Ophthalmol. 20;41(4):449–456. doi:10.1016/S0008-4182(06)80006-2

 PubMed Web of Science ®Google Scholar

Iordanous Y, Kent JS, Hutnik CM, Malvankar-Mehta MS. Projected cost comparison of trabectome, iStent, and endoscopic cyclophotocoagulation versus glaucoma medication in the Ontario Health Insurance Plan. J Glaucoma. 2014;23(2):e112–8. doi:10.1097/IJG.0b013e31829d9bc7.

 PubMed Web of Science ®Google Scholar

Availability of data and materials

All data is presented within the manuscript.