Are there any medications to combat retarded/delayed ejaculation?

No. There is no treatment, medical or surgical, for delayed ejaculation or no ejaculation (anejaculation). On the converse, there are several medications to help treat premature ejaculation.
Check prolactin. High prolactin levels can lead to anejaculation and can be treated with Cabergoline or bromcriptine. Additionally, some men respond to penile vibratory stimulation if there is a neurologic component to the anejaculation.

Related Questions

Is there any way to combat delayed ejaculation caused by ssri's?

Not really. Delayed ejaculation or anorgasmia is a side effect of ssris. In fact, certain ssris are used in the treatment of premature ejaculation. Reducing the dose or the frequency of the ssri may reduce this symptom, but it is unlikely to go away if already present.
A few things. There's a few things that can be tried for delayed ejaculation from ssris. 1.Chang. Some ssris have less of this. (eg. Zoloft) 2. Add wellbutrin. 3 lower dose and take it after sex. 4. Viagra (harder=sooner) 5. Change to a different type of antidepressants, such as Remeron or viibryd (vilazodone hydrochloride). Work with a doctor who knows how important this is to you and won't settle for 75%. Persistence wins the day!

What is the time to spend on sexual intercourse that can be termed retarded or delayed ejaculation?

Couple dependent. Sexual intercourse should be plearureable both partners. It should be terminated if one or other of the partners no longer enjoys it. Termination may thus be necessary before both parters acheive orgasm. Or when one partner wishes to terminate if intercourse continues beyond orgasm for both partners. In short, it is "retarded" if and when intercourse becomes unpleasant!