Loans Payable, Long-Term Debt and Other Commitments

Loans payable at December 31, 2018 included $5.1 billion of commercial paper and $149 million of long-dated notes that are subject to repayment at the option of the holders. Loans payable at December 31, 2017 included $3.0 billion of notes due in 2018 and $73 million of long-dated notes that are subject to repayment at the option of the holders. The weighted-average interest rate of commercial paper borrowings was 2.09% and 0.85% for the years ended December 31, 2018 and 2017, respectively.

Long-term debt at December 31 consisted of:



	2018		2017
2.75% notes due 2025	$	2,490	$	2,488
3.70% notes due 2045	1,974		1,973
2.80% notes due 2023	1,745		1,744
4.15% notes due 2043	1,237		1,237
1.85% notes due 2020	1,231		1,232
2.35% notes due 2022	1,214		1,220
1.125% euro-denominated notes due 2021	1,134		1,185
3.875% notes due 2021	1,132		1,140
1.875% euro-denominated notes due 2026	1,127		1,178
2.40% notes due 2022	983		993
6.50% notes due 2033	726		729
Floating-rate notes due 2020	699		699
0.50% euro-denominated notes due 2024	565		591
1.375% euro-denominated notes due 2036	561		587
2.50% euro-denominated notes due 2034	560		585
3.60% notes due 2042	490		489
6.55% notes due 2037	414		415
5.75% notes due 2036	338		338
5.95% debentures due 2028	306		306
5.85% notes due 2039	270		270
6.40% debentures due 2028	250		250
6.30% debentures due 2026	135		135
5.00% notes due 2019	—		1,260
Other	225		309
	$	19,806	$	21,353

Other (as presented in the table above) includes $223 million and $300 million at December 31, 2018 and 2017, respectively, of borrowings at variable rates that resulted in effective interest rates of 2.27% and 1.42% for 2018 and 2017, respectively.

With the exception of the 6.30% debentures due 2026, the notes listed in the table above are redeemable in whole or in part, at Merck’s option at any time, at varying redemption prices.

In December 2018, the Company exercised a make-whole provision on its $1.25 billion, 5.00% notes due 2019 and repaid this debt. In November 2017, the Company launched tender offers for certain outstanding notes and debentures. The Company paid $810 million in aggregate consideration (applicable purchase price together with accrued interest) to redeem $585 million principal amount of debt that was validly tendered in connection with the tender offers and recognized a loss on extinguishment of debt of $191 million in 2017.

Effective as of November 3, 2009, the Company executed a full and unconditional guarantee of the then existing debt of its subsidiary Merck Sharp & Dohme Corp. (MSD) and MSD executed a full and unconditional guarantee of the then existing debt of the Company (excluding commercial paper), including for payments of principal and interest. These guarantees do not extend to debt issued subsequent to that date.

Certain of the Company’s borrowings require that Merck comply with covenants and, at December 31, 2018, the Company was in compliance with these covenants.

The aggregate maturities of long-term debt for each of the next five years are as follows: 2019, no maturities; 2020, $1.9 billion; 2021, $2.3 billion; 2022, $2.2 billion; 2023, $1.7 billion.

The Company has a $6.0 billion credit facility that matures in June 2023. The facility provides backup liquidity for the Company’s commercial paper borrowing facility and is to be used for general corporate purposes. The Company has not drawn funding from this facility.

Rental expense under operating leases, net of sublease income, was $322 million in 2018, $327 million in 2017 and $292 million in 2016. The minimum aggregate rental commitments under noncancellable leases are as follows: 2019, $188 million; 2020, $198 million; 2021, $150 million; 2022, $134 million; 2023, $84 million and thereafter, $243 million. The Company has no significant capital leases.