It is unlikely that the medication your husband is taking is the cause of the difficulty in conceiving, as very few drugs have been shown to affect male fertility by decreasing testosterone production. However, it is important to ensure that your husband's pain is adequately relieved, as uncontrolled pain can have a negative impact on fertility. It may be helpful for your husband to try partially relieving his pain with acetaminophen in addition to the current medication, under the guidance of a pharmacist. Additionally, following some tips to increase fertility and not worrying too soon about a delay in conception is recommended, as it can take up to a year for some couples to conceive. If after a year you are still struggling to conceive and your husband is still taking the medication, you may want to consider discussing alternatives with a healthcare professional.